Automatic Shelf Registration Statement on Form N-2 for Well-known Seasoned Issuers (n-2asr)

As filed with the Securities and Exchange Commission on June 23, 2022

1933 Act File No. 333 -

1940 Act File No. 811-22673

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form N-2

(Check appropriate box or boxes)

REGISTRATION STATEMENT

☒

UNDER
THE SECURITIES ACT OF 1933
Pre-Effective Amendment No.

☐

Post-Effective Amendment No.

☐

And

REGISTRATION STATEMENT

UNDER
THE INVESTMENT COMPANY ACT OF 1940

☒

Amendment No. 16

☒

PIMCO DYNAMIC INCOME FUND

(Exact Name of Registrant as Specified in Charter)

1633 Broadway
New York, New York 10019

(Address of Principal Executive Offices)
(Number, Street, City, State, Zip Code)

(888) 877-4626

(Registrant’s Telephone Number, including Area Code)

Ryan G. Leshaw
c/o Pacific Investment Management Company LLC
650 Newport Center Drive
Newport Beach, California 92660

(Name and Address (Number, Street, City, State, Zip Code) of Agent for Service)

Copies of Communications to:

David C. Sullivan, Esq.

Ropes & Gray LLP

Prudential Tower, 800 Boylston Street

Boston, Massachusetts 02199

Douglas P. Dick, Esq.

Adam T. Teufel, Esq.

Dechert LLP

1900 K Street, N.W.

Washington, D.C. 20006

Approximate Date of Proposed Public Offering:
From time to time after the effective date of this Registration Statement.

☐	Check box if the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans.
☒	Check box if any securities being registered on this Form will be offered on a delayed or continuous basis in reliance on Rule 415 under the Securities Act of 1933 (“Securities Act”), other than securities offered in connection with a dividend reinvestment plan.
☒	Check box if this Form is a registration statement pursuant to General Instruction A.2 or a post-effective amendment thereto.
☒	Check box if this Form is a registration statement pursuant to General Instruction B or a post-effective amendment thereto that will become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act.
☐	Check box if this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction B to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act.

It is proposed that this filing will become effective (check appropriate box):
☐	when declared effective pursuant to Section 8(c), or as follows:

If appropriate, check the following box:
☐	This post-effective amendment designates a new effective date for a previously filed post-effective amendment.
☐	This Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, and the Securities Act registration statement number of the earlier effective registration statement for the same offering is:
☐	This Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, and the Securities Act registration statement number of the earlier effective registration statement for the same offering is:
☐	This Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, and the Securities Act registration statement number of the earlier effective registration statement for the same offering is:

Check each box that appropriately characterizes the Registrant:
☒	Registered Closed-End Fund (closed-end company that is registered under the Investment Company Act of 1940 (“Investment Company Act”)).
☐	Business Development Company (closed-end company that intends or has elected to be regulated as a business development company under the Investment Company Act).
☐	Interval Fund (Registered Closed-End Fund or a Business Development Company that makes periodic repurchase offers under Rule 23c-3 under the Investment Company Act).
☒	A.2 Qualified (qualified to register securities pursuant to General Instruction A.2 of this Form).
☒	Well-Known Seasoned Issuer (as defined by Rule 405 under the Securities Act).
☐	Emerging Growth Company (as defined by Rule 12b-2 under the Securities Exchange Act of 1934 (“Exchange Act”).
☐	If an Emerging Growth Company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of Securities Act.
☐	New Registrant (registered or regulated under the Investment Company Act for less than 12 calendar months preceding this filing).

Closed-End Funds

Base Prospectus

June 23, 2022

PIMCO Dynamic Income Fund

$1,000,000,000	Common Shares
PIMCO Dynamic Income Fund	PDI

Neither the U.S. Securities and Exchange Commission nor the U.S. Commodity Futures Trading Commission has approved or disapproved of these securities or determined that this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The Fund. PIMCO Dynamic Income Fund (the “Fund”) is a diversified, closed-end management investment company that commenced operations on May 30, 2012, following the initial public offering of its common shares.

Investment Objectives. The Fund seeks current income as a primary objective and capital appreciation as a secondary objective.

Investment Strategy. The Fund seeks to achieve its investment objectives by utilizing a dynamic asset allocation strategy that focuses on duration management, credit quality analysis, risk management techniques and broad diversification among issuers, industries and sectors. The Fund normally invests in a portfolio that consists primarily of corporate debt obligations of varying maturities, other corporate income-producing securities, and income-producing securities of non-corporate issuers. In managing the Fund, Pacific Investment Management Company LLC, the Fund’s investment manager (“PIMCO” or the “Investment Manager”), employs an active approach to allocation among multiple fixed income sectors based on, among other things, market conditions, valuation assessments and economic outlook, credit market trends and other economic factors. The Fund focuses on seeking income generating investment ideas across multiple fixed income sectors, with an emphasis on seeking opportunities in developed and emerging global credit markets.

The Fund’s common shares of beneficial interest, par value $0.00001 per share (the “Common Shares”), are listed on the New York Stock Exchange (“NYSE”) under the symbol PDI. The last reported sale price of the Common Shares, as reported by the NYSE on May 31, 2022, was $22.55 per Common Share. The net asset value (“NAV”) of the Common Shares at the close of business on May 31, 2022, was $21.43 per Common Share.

Investment in the Fund’s Common Shares involves substantial risks arising from, among other strategies, the Fund’s ability to invest in debt instruments that are, at the time of purchase, rated below investment grade (below Baa3 by Moody’s Investors Service, Inc. or below BBB- by either S&P Global Ratings or Fitch, Inc.) or unrated but determined by PIMCO to be of comparable quality, the Fund’s exposure to foreign (including emerging market) securities and currencies and to mortgage-related and other asset-backed securities, and the Fund’s use of leverage. Debt securities of below investment grade quality are regarded as having predominantly speculative characteristics with respect to capacity to pay interest and to repay principal, and are commonly referred to as “high yield” securities or “junk bonds.” The Fund’s exposure

to foreign securities and currencies, and particularly to emerging markets securities and currencies, involves special risks, including foreign currency risk and the risk that the securities may decline in response to unfavorable political and legal developments, unreliable or untimely information or economic and financial instability. Mortgage-related and other asset-backed securities are subject to extension and prepayment risk and often have complicated structures that make them difficult to value. Because of the risks associated with

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investing in high yield securities, foreign (including emerging market) securities (and related exposure to foreign currencies) and mortgage-related and other asset-backed securities, and

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using leverage, an investment in the Fund should be considered speculative. Before investing in the Common Shares, you should read the discussion of the principal risks of investing in the Fund in “Principal Risks of the Fund.” Certain of these risks are summarized in “Prospectus Summary—Principal Risks of the Fund.” The Fund cannot assure you that it will achieve its investment objectives, and you could lose all of your investment in the Fund.

Under normal circumstances, the Fund will have a short to intermediate average portfolio duration (i.e., within a zero to eight year range), as calculated by the Investment Manager, although it may be shorter or longer at any time or from time to time depending on market conditions and other factors.

Portfolio Contents. The Fund normally invests worldwide in a portfolio of debt obligations and other income-producing securities of any type and credit quality and with varying maturities and related derivative instruments.

The Fund may invest in investment grade debt securities and below investment grade debt securities (commonly referred to as “high yield” securities or “junk bonds”), including securities of defaulted and stressed issuers. The Fund may invest without limitation in securities of U.S. issuers. Subject to the limit described below on investments in securities and instruments that are economically tied to “emerging market” countries, the Fund may invest without limitation in securities of foreign (non-U.S.) issuers, securities traded principally outside of the United States, and securities denominated in currencies other than the U.S. dollar. The Fund may invest without limitation in investment grade sovereign debt denominated in the relevant country’s local currency with less than one year remaining to maturity (“short-term investment grade sovereign debt”), including short-term investment grade sovereign debt issued by emerging market issuers. The Fund may invest up to 40% of its total assets in securities and instruments that are economically tied to “emerging market” countries other than investments in short-term investment grade sovereign debt issued by emerging market issuers, where as noted above there is no limit. The Fund may also invest directly in foreign currencies, including local emerging market currencies. The Fund will not normally invest directly in common stocks of operating companies. However, the Fund may own and hold common stocks of operating companies in its portfolio from time to time in connection with a corporate action, the restructuring of a debt instrument, or through the conversion of a convertible security held by the Fund.

The Fund may, but is not required to, utilize various derivative strategies (both long and short positions) involving the purchase or sale of futures and forward contracts (including foreign currency exchange contracts), call and put options, credit default swaps, total return swaps, basis swaps and other swap agreements and other derivative instruments for investment purposes, leveraging purposes or in an attempt to hedge against market, credit, interest rate, currency and other risks in the portfolio. The Fund may purchase and sell securities on a when-issued, delayed delivery or forward commitment basis and may engage in short sales.

Substantially all of the Fund’s portfolio may consist of below investment-grade securities and/or mortgage-related or other types of asset backed securities. The Fund will not normally invest more than 20% of its total assets in debt instruments, other than mortgage-related or asset-backed securities, that are, at the time of purchase, rated CCC+ or lower by S&P and Fitch and Caa1 or lower by Moody’s, or that are unrated but determined by PIMCO to be of comparable quality to securities so rated. The Fund may invest without limitation in mortgage-related and other asset-backed securities regardless of rating—i.e., of any credit quality.

The Fund may invest in securities that have not been registered for public sale in the U.S. or relevant non-U.S. jurisdictions, including without limitation securities eligible for purchase and sale pursuant to Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”), or relevant provisions of applicable non-U.S. law, and other securities issued in private placements. The Fund may also invest in securities of other investment companies (including those advised by PIMCO), including, without limitation, domestic and foreign exchange-traded funds (ETFs). The Fund may invest in real estate investment trusts (“REITs”). The Fund may invest in securities of companies with any market capitalization, including small and medium capitalizations.

The Fund may normally invest up to 40% of its total assets in bank loans (including, among others, senior loans, delayed funding loans, revolving credit facilities, covenant-lite obligations, and loan participations and assignments). The Fund will not normally invest more than 10% of its total assets in convertible debt securities, including synthetic convertible debt securities. The Fund may also invest in preferred securities.

As a matter of fundamental policy, the Fund will normally invest at least 25% of its total assets in privately-issued (commonly known as “non-agency”) mortgage-related securities.

The Fund may invest without limitation in illiquid investments (i.e., investments that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment). The Fund may make investments in debt instruments and other securities directly or through one or more wholly-owned subsidiaries (each, a “Subsidiary” and collectively, the “Subsidiaries”). Each Subsidiary may invest, for example, in whole loans or in shares, certificates, notes or other securities representing the right to receive principal and interest payments due on fractions of whole loans or pools of whole loans, or any

other security or other instrument that the Fund may hold directly. References herein to the Fund include, as appropriate, Subsidiaries through which the Fund may gain exposure to investments. The Fund may be exposed to the different types of investments described below through its investments in its Subsidiaries. The allocation of the Fund’s assets to a Subsidiary will vary over time and will likely not include all of the different types of investments described herein at any given time.

The Fund may invest, either directly or indirectly through Subsidiaries in shares, certificates, notes or other securities issued by a special purpose entity (“SPE”) sponsored by an alternative lending platform or its affiliates (the “Sponsor”) that represent the right to receive principal and interest payments due on pools of whole loans or fractions of whole loans, which may (or may not) be issued by the Sponsor, held by the SPE (“Alt Lending ABS”). Any such Alt Lending ABS may be backed by consumer, residential or other loans.

When acquiring loans or purchasing Alt Lending ABS, the Fund is not restricted by any particular borrower credit criteria. Accordingly, certain loans acquired by the Fund or any underlying Alt Lending ABS purchased by the Fund may be subprime in quality, or may become subprime in quality.

Leverage. The Fund currently utilizes leverage principally through reverse repurchase agreements, and may also obtain leverage through dollar rolls and borrowings, such as through bank loans or commercial paper and/or other credit facilities. The Fund may also enter into transactions other than those noted above that may give rise to a form of leverage including, among others, futures and forward contracts (including foreign currency exchange contracts), total return swaps and other derivative transactions, loans of portfolio securities, short sales, when-issued, delayed delivery and forward commitment transactions and selling credit default swaps. The Fund may also determine to issue preferred or other types of senior securities to add leverage to its portfolio. The Fund’s Board of Trustees may authorize the issuance of preferred shares without the approval of holders of Common Shares (“Common Shareholders”). If the Fund issues preferred shares in the future, all costs and expenses relating to the issuance and ongoing maintenance of the preferred shares will be borne by the Common Shareholders, and these costs and expenses may be significant. Depending upon market conditions and other factors, the Fund may or may not determine to add leverage following an offering to maintain or increase the total amount of leverage (as a percentage of the Fund’s total assets) that the Fund currently maintains, taking into account the additional assets raised through the issuance of Common Shares in such offering. The Fund utilizes certain kinds of leverage, such as reverse repurchase agreements and selling credit default swaps, opportunistically and may choose to increase or decrease, or eliminate entirely, its use of such leverage over time and from time to time based on PIMCO’s assessment of the yield curve environment, interest rate trends, market conditions and other factors. If the Fund determines to add leverage following an offering, it is not possible to predict with accuracy the precise amount of leverage that would be added, in part because it is not possible to predict the number of Common Shares that ultimately will be sold in an offering or series of offerings. To the extent that the Fund does not add additional leverage following an offering, the Fund’s total amount of leverage as a percentage of its total assets will decrease, which could result in a reduction of investment income available for distribution to the Common Shareholders.

Under normal market conditions, the Fund will limit its use of leverage from any combination of reverse repurchase agreements or dollar roll transactions (whether or not these instruments are covered), borrowings (i.e., loans or lines of credit from banks or other credit facilities), any future issuance of preferred shares and, to the extent described in this prospectus under the section entitled “Use of Leverage,” credit default swaps, other swap agreements and futures contracts, such that the assets attributable to the use of such leverage will not exceed 50% of the Fund’s total assets (including, for purposes of the 50% limit, the amounts of leverage obtained through the use of such instruments). The Investment Company Act of 1940, as amended (the “1940 Act”), and the rules and regulations promulgated thereunder (the “1940 Act”), also generally limits the extent to which the Fund may utilize uncovered reverse repurchase agreements and borrowings, together with any other senior securities representing indebtedness, to 33 1∕13% of the Fund’s total net assets at the time utilized. See “Use of Leverage.” By using leverage, the Fund will seek to obtain a higher return for holders of common shares than if the Fund did not use leverage. Leveraging is a speculative technique and there are special risks and costs involved. There can be no assurance that a leveraging strategy will be used or that it will be successful during any period in which it is employed. See “Use of Leverage” and “Principal Risks of the Fund—Leverage Risk.”

Additional Information. This prospectus is part of a registration statement that the Fund has filed with the U.S. Securities and Exchange Commission (the “SEC”), as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act, using the “shelf” registration process. Under the shelf registration process, the Fund may offer, from time to time, in one or more offerings, up to $1,000,000,000 of the Common Shares on terms to be determined at the time of the offering. This prospectus provides you with a general description of the Common Shares that the Fund may offer. Each time the Fund uses this prospectus to offer Common Shares, the Fund will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add, update or change

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information contained in this prospectus. You should read this prospectus and the applicable prospectus supplement, which contain important information about the Fund, carefully before you invest in the Common Shares. Common Shares may be offered directly to one or more purchasers, through agents designated from time to time by the Fund, or to or through underwriters or dealers. The prospectus supplement relating to an offering will identify any agents, underwriters or dealers involved in the sale of Common Shares, and will set forth any applicable purchase price, fee, commission or discount arrangement between the Fund and its agents or underwriters, or among the Fund’s underwriters, or the basis upon which such amount may be calculated. See “Plan of Distribution.” The Fund may not sell any Common Shares through agents, underwriters or dealers without delivery or deemed delivery of a prospectus supplement describing the method and terms of the particular offering of the Common Shares.

You should retain this prospectus and any prospectus supplement for future reference. A Statement of Additional Information, dated June 23, 2022, containing additional information about the Fund has been filed with the SEC and is incorporated by reference in its entirety into this prospectus. You may request a free copy of the Statement of Additional Information, request the Fund’s most recent annual and semiannual reports, request information about the Fund and make shareholder inquiries by calling toll-free (844)-33-PIMCO (844-337-4626) or by writing to the Fund at c/o Pacific Investment Management Company LLC, 1633 Broadway, New York, New York 10019. The Fund’s Statement of Additional Information and most recent annual and semiannual reports are available, free of charge, on the Fund’s website (http://www.pimco.com/prospectuses). You can obtain the same information, free of charge, from the SEC’s website (http://www.sec.gov).

The Common Shares do not represent a deposit or obligation of, and are not guaranteed or endorsed by, any bank or other insured depository institution, and are not federally insured by the Federal Deposit Insurance Corporation, the Federal Reserve Board or any other government agency.

The Fund has not authorized anyone to provide you with information other than that contained or incorporated by reference in this prospectus or any applicable prospectus supplement, and any free writing prospectus that the Fund distributes. The Fund does not take any responsibility for, and does not provide any assurances as to the reliability of, any other information that others may give you. The Fund is not making an offer of these securities in any jurisdiction where the offer is not permitted. You should not assume that the information contained in this prospectus or any applicable prospectus supplement is accurate as of any date other than the date on the front hereof or thereof. The Fund’s business, financial condition, results of operations and prospects may have changed since that date.

Table of Contents

	Page
Prospectus Summary	1
Summary of Fund Expenses	28
Financial Highlights	29
Use of Proceeds	31
The Fund	31
Investment Objectives and Policies	31
Portfolio Contents	32
Use of Leverage	54
Principal Risks of the Fund	56
How the Fund Manages Risk	82
Management of the Fund	84
Net Asset Value	87
Distributions	88
Dividend Reinvestment Plan	89
Description of Capital Structure	91
Plan of Distribution	91
Market and Net Asset Value Information	92
Anti-Takeover and Other Provisions in the Declaration of Trust	92
Repurchase of Common Shares; Conversion to Open-End Fund	93
Tax Matters	94
Shareholder Servicing Agent, Custodian and Transfer Agent	96
Independent Registered Public Accounting Firm	96
Legal Matters	96
Incorporation by Reference	96
Appendix A - Description of Securities Ratings	A- 1

PIMCO Dynamic Income Fund

Prospectus Summary

This is only a summary. This summary may not contain all of the information that you should consider before investing in the Fund’s common shares of beneficial interest, par value $0.00001 per share (the “Common Shares”). You should review the more detailed information contained in this prospectus and in any related prospectus supplement and in any related prospectus supplement and in the Statement of Additional Information, especially the information set forth under the heading “Principal Risks of the Fund.”

The Fund

PIMCO Dynamic Income Fund (the “Fund”) is a diversified, closed-end management investment company. The Fund commenced operations on May 30, 2012, following the initial public offering of its Common Shares.

The Common Shares are listed on the New York Stock Exchange (“NYSE”) under the symbol “PDI.” As of May 31, 2022, the net assets of the Fund attributable to Common Shares were $4,832,084,446 and the Fund had outstanding 225,437,136 Common Shares. The last reported sale price of the Common Shares, as reported by the NYSE on May 31, 2022, was $22.55 per Common Share. The net asset value (“NAV”) of the Common Shares at the close of business on May 31, 2022, was $21.43 per Common Share. See “Description of Capital Structure.”

The Offering

The Fund may offer, from time to time, in one or more offerings, up to $1,000,000,000 of Common Shares on terms to be determined at the time of the offering. The Common Shares may be offered at prices and on terms to be set forth in one or more prospectus supplements. You should read this prospectus and the applicable prospectus supplement carefully before you invest in the Common Shares. Common Shares may be offered directly to one or more purchasers, through agents designated from time to time by the Fund, or to or through underwriters or dealers. The prospectus supplement relating to an offering will identify any agents, underwriters or dealers involved in the sale of Common Shares, and will set forth any applicable purchase price, fee, commission or discount arrangement between the Fund and its agents or underwriters, or among the Fund’s underwriters, or the basis upon which such amount may be calculated. See “Plan of Distribution.” The Fund may not sell any Common Shares through agents, underwriters or dealers without delivery or deemed delivery of a prospectus supplement describing the method and terms of the particular offering of the Common Shares.

Use of Proceeds

Fund’s investment objectives and policies, and except to the extent proceeds are held in cash to pay dividends or expenses, or for temporary defensive purposes. See “Use of Proceeds” below.

Investment Objectives and Policies

When used in this prospectus, the term “invest” includes both direct investing and indirect investing and the term “investments” includes both direct investments and indirect investments. For example, the Fund may invest indirectly by investing in derivatives or through wholly-owned subsidiaries (each, a “Subsidiary” and collectively, the “Subsidiaries”). References herein to the Fund include, as appropriate, Subsidiaries through which the Fund may gain exposure to investments. The Fund may be exposed to the different types of investments described below through its investments in its Subsidiaries. The allocation of the Fund’s assets to a Subsidiary will vary over time and will likely not include all of the different types of investments described herein at any given time.

The Fund seeks current income as a primary objective and capital appreciation as a secondary objective. The Fund seeks to achieve its investment objectives by utilizing a dynamic asset allocation strategy among multiple fixed income sectors in the global credit markets, including corporate debt (including, among other things, fixed-, variable- and floating-rate bonds, bank loans, convertible securities and stressed debt securities issued by U.S. or foreign (non-U.S. and emerging market) corporations or other business entities), mortgage-related and other asset-backed securities, government and sovereign debt, taxable municipal bonds and other fixed-, variable- and floating-rate income-producing securities of U.S. and foreign (including emerging market) issuers. The Fund may invest in investment grade debt securities and below investment grade debt securities (commonly referred to as “high yield” securities or “junk bonds”), including securities of defaulted and stressed issuers. The types of securities and instruments in which the Fund may invest are summarized under “Portfolio Contents” below. The Fund cannot assure you that it will achieve its investment objectives, and you could lose all of your investment in the Fund.

Portfolio Management Strategies

Dynamic Allocation Strategy. In managing the Fund, the Fund’s investment manager, Pacific Investment Management Company LLC (“PIMCO” or the “Investment Manager”), employs an active approach to allocation among multiple fixed income sectors based on, among other things, market conditions, valuation assessments, economic outlook, credit market trends and other economic factors. With PIMCO’s macroeconomic analysis as the basis for top-down investment decisions, including geographic and credit sector emphasis, PIMCO manages the Fund with a focus on seeking income generating investment ideas across multiple fixed income sectors, with an emphasis on seeking opportunities in developed and emerging global credit markets. PIMCO may choose to focus on particular countries/regions, asset classes, industries and sectors to the exclusion of others at any time and from time to time based on market conditions and other factors. The relative value assessment within fixed-income sectors draws

1 Closed-End Funds | Base Prospectus

Base Prospectus

on PIMCO’s regional and sector specialist insights. As a matter of fundamental policy, the Fund will normally invest at least 25% of its total assets in privately-issued (commonly known as “non-agency”) mortgage-related securities. The Fund will observe various investment guidelines as summarized below.

Investment Selection Strategies. Once the Fund’s top-down, portfolio positioning decisions have been made as described above, PIMCO selects particular investments for the Fund by employing a bottom-up, disciplined credit approach which is driven by fundamental, independent research within each sector/asset class represented in the Fund, with a focus on identifying securities and other instruments with solid and/or improving fundamentals.

PIMCO utilizes strategies that focus on credit quality analysis, duration management and other risk management techniques. PIMCO attempts to identify, through fundamental research driven by independent credit analysis and proprietary analytical tools, debt obligations and other income-producing securities that provide current income and/or opportunities for capital appreciation based on its analysis of the issuer’s credit characteristics and the position of the security in the issuer’s capital structure.

Consideration of yield is only one component of the portfolio managers’ approach in managing the Fund. PIMCO also attempts to identify investments that may appreciate in value based on PIMCO’s assessment of the issuer’s credit characteristics, forecast for interest rates and outlook for particular countries/regions, currencies, industries, sectors and the global economy and bond markets generally.

Credit Quality. The Fund may invest in debt instruments that are, at the time of purchase, rated below investment grade, or that are unrated but determined by PIMCO to be of comparable quality. However, the Fund will not normally invest more than 20% of its total assets in debt instruments, other than mortgage-related and other asset-backed securities, that are, at the time of purchase, rated CCC+ or lower by S&P Global Ratings (“S&P”) and Fitch, Inc. (“Fitch”) and Caa1 or lower by Moody’s Investors Services Inc. (“Moody’s”), or that are unrated but determined by PIMCO to be of comparable quality to securities so rated. The Fund may invest without limitation in mortgage-related and other asset-backed securities regardless of rating—i.e., of any credit quality. For purposes of applying the foregoing policies, in the case of securities with split ratings (i.e., a security receiving two different ratings from two different rating agencies), the Fund will apply the higher of the applicable ratings. Subject to the aforementioned investment restrictions, the Fund may invest in securities of stressed issuers which include securities at risk of being in default as to the repayment of principal and/or interest at the time of acquisition by the Fund or that are rated in the lower rating categories by one or more nationally recognized statistical rating organizations (for example, Ca or lower by Moody’s or CC or lower by S&P or Fitch) or, if unrated, are determined by PIMCO to be of comparable quality. Debt instruments of below investment grade quality are regarded as having predominantly speculative characteristics with respect to capacity to pay interest and to repay principal, and are commonly referred to as “high yield” securities or “junk bonds.” Debt instruments in the lowest investment grade

category also may be considered to possess some speculative characteristics. The Fund may, for hedging, investment or leveraging purposes, make use of credit default swaps, which are contracts whereby one party makes periodic payments to a counterparty in exchange for the right to receive from the counterparty a payment equal to the par (or other agreed-upon) value of a referenced debt obligation in the event of a default or other credit event by the issuer of the debt obligation.

Independent Credit Analysis. PIMCO relies primarily on its own analysis of the credit quality and risks associated with individual debt instruments considered for the Fund, rather than relying exclusively on rating agencies or third-party research. The Fund’s portfolio managers utilize this information in an attempt to manage credit risk and identify issuers, industries or sectors that are undervalued or that offer attractive yields relative to PIMCO’s assessment of their credit characteristics. This aspect of PIMCO’s capabilities will be particularly important to the extent that the Fund invests in high yield securities and in securities of emerging market issuers.

Duration Management. It is expected that the Fund normally will have a short to intermediate average portfolio duration (i.e., within a zero to eight year range), as calculated by PIMCO, although it may be shorter or longer at any time or from time to time depending on market conditions and other factors. For example, if the Fund has an average portfolio duration of eight years, a 1% increase in interest rates would tend to correspond to an 8% decrease in the value of the Fund’s debt portfolio. While the Fund seeks to maintain a short to intermediate average portfolio duration, there is no limit on the maturity or duration of any individual security in which the Fund may invest. Duration is a measure used to determine the sensitivity of a security’s price to changes in interest rates. The Fund’s duration strategy may entail maintaining a negative average portfolio duration from time to time, meaning the portfolio would tend to increase in value in response to an increase in interest rates. If the Fund has a negative average portfolio duration, a 1% increase in interest rates would tend to correspond to a 1% increase in the value of the Fund’s debt portfolio for every year of negative duration. A negative average portfolio duration would potentially benefit the Fund’s portfolio in an environment of rising market interest rates, but would generally adversely impact the portfolio in an environment of falling or neutral market interest rates. See “Principal Risks of the Fund—Interest Rate Risk.” PIMCO may also utilize certain strategies, including without limitation investments in structured notes or interest rate futures contracts or swap, cap, floor or collar transactions, for the purpose of reducing the interest rate sensitivity of the Fund’s portfolio, although there is no assurance that it will do so or that such strategies will be successful.

Portfolio Contents

The Fund normally invests worldwide in a portfolio of debt obligations and other income-producing securities of any type and credit quality and with varying maturities and related derivative instruments. The Fund’s portfolio of debt obligations and income-producing securities may include, without limitation, bonds, debentures, notes, and other

June 23, 2022 | Base Prospectus 2

PIMCO Dynamic Income Fund

debt securities of U.S. and foreign (non-U.S.) corporate and other issuers, including commercial paper; mortgage-related and other asset-backed securities issued by government agencies or other governmental entities or by private originators or issuers; U.S. Government securities; obligations of foreign governments or their sub-divisions, agencies and government sponsored enterprises and obligations of international agencies and supranational entities; municipal securities and other debt securities issued by states or local governments and their agencies, authorities and other government-sponsored enterprises, including taxable municipal securities (such as Build America Bonds); payment-in-kind securities (“PIKs”); zero-coupon bonds; inflation indexed bonds issued by both governments and corporations; structured notes, including hybrid or indexed securities; catastrophe bonds and other event-linked bonds; credit-linked notes; credit-linked trust instruments; structured credit products; bank loans (including, among others, senior loans, delayed funding loans, covenant-lite obligations, revolving credit facilities and loan participations and assignments); preferred securities; convertible debt securities (i.e., debt securities that may be converted at either a stated price or stated rate into underlying shares of common stock), including synthetic convertible debt securities (i.e., instruments created through a combination of separate securities that possess the two principal characteristics of a traditional convertible security, such as an income producing security and the right to acquire an equity security) and contingent convertible securities; and bank certificates of deposit, fixed time deposits and bankers’ acceptances. The rate of interest on an income producing security may be fixed, floating or variable. Certain corporate income-producing securities, such as convertible bonds, also may include the right to participate in equity appreciation. The Fund may invest in debt securities of stressed issuers. Subject to the investment limitations described under “Credit Quality” above, at any given time and from time to time, substantially all of the Fund’s portfolio may consist of below investment grade securities and/or mortgage-related or other types of asset backed securities. The Fund may invest in various levels of the capital structure of an issuer of mortgage-backed or asset-backed securities, including the equity or “first loss” tranche. The Fund may also invest, as a third party purchaser, in risk retention tranches of commercial mortgage-backed securities or other eligible securitizations, which are eligible residual interests typically held by the sponsors of such securitizations pursuant to the final rules implementing the credit risk retention requirements of Section 941 of the Dodd-Frank Act.

The Fund may invest without limitation in securities of U.S. issuers. Subject to the limit described below on investments in securities and instruments that are economically tied to “emerging market” countries, the Fund may invest without limitation in securities of foreign (non-U.S.) issuers, securities traded principally outside of the United States, and securities denominated in currencies other than the U.S. dollar. The Fund may invest without limitation in investment grade sovereign debt denominated in the relevant country’s local currency with less than one year remaining to maturity (“short-term investment grade sovereign debt”), including short-term investment grade sovereign debt issued by emerging market issuers. The Fund may invest up to 40% of its total

assets in securities and instruments that are economically tied to “emerging market” countries other than investments in short-term investment grade sovereign debt issued by emerging market issuers, where as noted above there is no limit. The Fund may also invest directly in foreign currencies, including local emerging market currencies.

The Fund may normally invest up to 40% of its total assets in bank loans (including, among others, senior loans, delayed funding loans, covenant-lite obligations, revolving credit facilities and loan participations and assignments). The Fund will not normally invest more than 10% of its total assets in convertible debt securities (i.e., debt securities that may be converted at either a stated price or stated rate into underlying shares of common stock), including synthetic convertible debt securities (i.e., instruments created through a combination of separate securities that possess the two principal characteristics of a traditional convertible security, i.e., an income-producing security and the right to acquire an equity security). The Fund may also invest in preferred securities.

As a matter of fundamental policy, the Fund normally invests at least 25% of its total assets in privately-issued (commonly known as “non-agency”) mortgage-related securities.

The Fund will not normally invest directly in common stocks of operating companies. However, the Fund may own and hold common stocks in its portfolio from time to time in connection with a corporate action or the restructuring of a debt instrument, or through the conversion of a convertible security held by the Fund. Common stocks include common shares and other common equity interest issued by public or private issuers.

The Fund may invest in securities that have not been registered for public sale in the U.S. or relevant non-U.S. jurisdictions, including without limitation securities eligible for purchase and sale pursuant to Rule 144A under the Securities Act, or relevant provisions of applicable non-U.S. law, and other securities issued in private placements. The Fund may invest in securities of other investment companies (including those advised by PIMCO), including, without limitation, domestic and foreign exchange-traded (ETFs). The Fund may invest in real estate investment trusts (“REITs”). The Fund may invest in securities of companies with any market capitalization, including small and medium capitalizations.

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Base Prospectus

The Fund may make investments in debt instruments and other securities directly or through one or more Subsidiaries. Each Subsidiary may invest, for example, in or whole loans or in shares, certificates, notes or other securities representing the right to receive principal and interest payments due on fractions of whole loans or pools of whole loans or any other security or other instrument that the Fund may hold directly. The Fund will treat the assets of its Subsidiaries as assets of the Fund for purposes of determining compliance with various provisions of the 1940 Act applicable to the Fund, including those relating to investment policies (Section 8), capital structure and leverage (Section 18) and affiliated transactions and custody (Section 17).

The Fund may invest, either directly or indirectly through its Subsidiaries, in Alt Lending ABS backed by consumer, residential or other loans, issued by an SPE sponsored by an online or alternative lending platform or an affiliate thereof.

When acquiring loans or purchasing Alt Lending ABS, the Fund is not restricted by any particular borrower credit criteria. Accordingly, certain loans acquired by the Fund or underlying any Alt Lending ABS purchased by the Fund may be subprime in quality, or may become subprime in quality.

When acquiring and/or originating loans, or purchasing Alt Lending ABS, the Fund is not restricted by any particular borrower credit criteria. Accordingly, certain loans acquired or originated by the Fund or underlying any Alt Lending ABS purchased by the Fund may be subprime in quality, or may become subprime in quality.

Leverage

The Fund may obtain leverage through reverse repurchase agreements, dollar rolls or borrowings, such as through bank loans or commercial paper or other credit facilities. The Fund may also enter into transactions other than those noted above that may give rise to a form of leverage including, among others, futures and forward contracts (including foreign currency exchange contracts), total return swaps and other derivative transactions, loans of portfolio securities, short sales, when-issued, delayed delivery and forward commitment transactions and selling credit default swaps. The Fund may also determine to issue preferred shares or other types of senior securities to add leverage to its portfolio. The Fund’s Board of Trustees may authorize the issuance of preferred shares without the approval of Common Shareholders. If the Fund issues preferred shares in the future, all costs and expenses relating to the issuance and ongoing maintenance of the preferred shares will be borne by the Common Shareholders, and these costs and expenses may be significant.

Under normal market conditions, the Fund will limit its use of leverage from any combination of (i) reverse repurchase agreements or dollar roll transactions (whether or not these instruments are covered as discussed below), (ii), borrowings (i.e., loans or lines of credit from banks or other credit facilities), (iii) any future issuance of preferred shares, and (iv) to the extent described below, credit default swaps, other swap agreements and futures contracts (whether or not these instruments are covered with segregated assets as discussed below) such that the assets attributable to the use of such leverage will not exceed 50% of the Fund’s total assets (including, for purposes of the 50% limit, the amounts of leverage obtained through the use of such instruments) (the “50% policy”). For these purposes, assets attributable to the use of leverage from credit default swaps, other swap agreements and futures contracts will be determined based on the current market value of the instrument if it is cash settled or based on the notional value of the instrument if it is not cash settled. In addition, assets attributable to credit default swaps, other swap agreements or futures contracts will not be counted towards the 50% policy to the extent that the Fund owns offsetting positions or enters into offsetting transactions.

Depending upon market conditions and other factors, the Fund may or may not determine to add leverage following an offering to maintain or increase the total amount of leverage (as a percentage of the Fund’s total assets) that the Fund currently maintains, taking into account the additional assets raised through the issuance of Common Shares in such offering. The Fund utilizes certain kinds of leverage, such as reverse repurchase agreements and selling credit default swaps, opportunistically and may choose to increase or decrease, or eliminate entirely, its use of such leverage over time and from time to time based on PIMCO’s assessment of the yield curve environment, interest rate trends, market conditions and other factors. If the Fund determines to add leverage following an offering, it is not possible to predict with accuracy the precise amount of leverage that would be added, in part because it is not possible to predict the number of Common Shares that ultimately will be sold in an offering or series of offerings. To the extent that the Fund does not add additional leverage following an offering,

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PIMCO Dynamic Income Fund

the Fund’s total amount of leverage as a percentage of its total assets will decrease, which could result in a reduction of investment income available for distribution to Common Shareholders.

The net proceeds the Fund obtains from reverse repurchase agreements or other forms of leverage utilized, if any, will be invested in accordance with the Fund’s investment objectives and policies as described in this prospectus and any prospectus supplement. So long as the rate of return, net of applicable Fund expenses, on the debt obligations and other investments purchased by the Fund exceeds the costs to the Fund of the leverage it utilizes, the investment of the Fund’s net assets attributable to leverage will generate more income than will be needed to pay the costs of the leverage. If so, and all other things being equal, the excess may be used to pay higher dividends to Common Shareholders than if the Fund were not so leveraged.

The 1940 Act also generally prohibits the Fund from engaging in most forms of leverage representing indebtedness other than preferred shares (including the use of reverse repurchase agreements, dollar rolls, bank loans, commercial paper or other credit facilities, credit default swaps, total return swaps and other derivative transactions, loans of portfolio securities, short sales and when-issued, delayed delivery and forward commitment transactions, to the extent that these instruments are not covered as described below) unless immediately after the issuance of the leverage the Fund has satisfied the asset coverage test with respect to senior securities representing indebtedness prescribed by the 1940 Act; that is, the value of the Fund’s total assets less all liabilities and indebtedness not represented by senior securities (for these purposes, “total net assets”) is at least 300% of the senior securities representing indebtedness (effectively limiting the use of leverage through senior securities representing indebtedness to 33 1∕13% of the Fund’s total net assets, including assets attributable to such leverage). In addition, the Fund is not permitted to declare any cash dividend or other distribution on its Common Shares unless, at the time of such declaration, this asset coverage test is satisfied. The Fund may (but is not required to) cover its commitments under reverse repurchase agreements, dollar rolls, derivatives and certain other instruments by the segregation of liquid assets, or by entering into offsetting transactions or owning positions covering its obligations. To the extent that certain of these instruments are so covered, they will not be considered “senior securities” under the 1940 Act and therefore will not be subject to the 1940 Act 300% asset coverage requirement otherwise applicable to forms of senior securities representing indebtedness used by the Fund. However, reverse repurchase agreements and other such instruments, even if covered, represent a form of economic leverage and create special risks. The use of these forms of leverage increases the volatility of the Fund’s investment portfolio and could result in larger losses to Common Shareholders than if these strategies were not used. See “Principal Risks of the Fund—Leverage Risk.” To the extent that the Fund engages in borrowings, it may prepay a portion of the principal amount of the borrowing to the extent necessary in order to maintain the required asset coverage. Failure to maintain certain asset coverage requirements could result in an event of default.

Leveraging is a speculative technique and there are special risks and costs involved. There is no assurance that the Fund will utilize reverse repurchase agreements, credit default swaps, total return swaps, dollar rolls or borrowings, issue preferred shares or utilize any other forms of leverage (such as the use of derivatives strategies). If used, there can be no assurance that the Fund’s leveraging strategies will result in a higher yield on your Common Shares. When leverage is used, the NAV and market price of the Common Shares and the yield to Common Shareholders will be more volatile. See “Principal Risks of the Fund—Leverage Risk.” In addition, dividend, interest and other expenses borne by the Fund with respect to its use of reverse repurchase agreements, credit default swaps, total return swaps, dollar rolls, borrowings, preferred shares or any other forms of leverage are borne by the Common Shareholders and result in a reduction of the NAV of the Common Shares. In addition, because the fees received by the Investment Manager are based on the Fund’s average daily “total managed assets” (including any assets attributable to any reverse repurchase agreements, dollar rolls, borrowings and preferred shares that may be outstanding) minus accrued liabilities (other than liabilities representing reverse repurchase agreements, dollar rolls and borrowings), the Investment Manager has a financial incentive for the Fund to use certain forms of leverage (e.g., reverse repurchase agreements, dollar rolls, borrowings and preferred shares), which may create a conflict of interest between the Investment Manager, on the one hand, and the Common Shareholders, on the other hand.

Please see “Use of Leverage” and “Principal Risks of the Fund—Leverage Risk” in the body of this prospectus for additional information regarding leverage and related risks.

Investment Manager

PIMCO serves as the investment manager of the Fund. Subject to the supervision of the Board of Trustees of the Fund (the “Board”). PIMCO is responsible for managing the investment activities of the Fund and the Fund’s business affairs and other administrative matters. Daniel J. Ivascyn, Alfred T. Murata and Joshua Anderson are jointly and primarily responsible for the day-to-day management of the Fund.

The Investment Manager receives an annual fee from the Fund, payable monthly, in an amount equal to 1.10% of the Fund’s average daily “total managed assets.” Total managed assets includes the total assets of the Fund (including assets attributable to any reverse repurchase agreements, dollar rolls, borrowings and preferred shares that may be outstanding) minus accrued liabilities (other than liabilities representing reverse repurchase agreements, dollar rolls and borrowings). For purposes of calculating total managed assets, the Fund’s derivative instruments will be valued based on their market value.

PIMCO is located at 650 Newport Center Drive, Newport Beach, CA, 92660. Organized in 1971, PIMCO provides investment management and advisory services to private accounts of institutional and individual clients and to registered investment companies. PIMCO is a majority-owned indirect subsidiary of Allianz SE, a publicly traded

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Base Prospectus

European insurance and financial services company. As of March 31, 2022, PIMCO had approximately $2.05 trillion in assets under management.

Dividends and Distributions

The Fund makes regular monthly cash distributions to Common Shareholders at a rate based upon the past and projected net income of the Fund. Subject to applicable law, the Fund may fund a portion of its distributions with gains from the sale of portfolio securities and other sources. The Fund’s dividend policy, as well as the dividend rate that the Fund pays on its Common Shares, may vary as portfolio and market conditions change, and will depend on a number of factors. There can be no assurance that a change in market conditions or other factors will not result in a change in the Fund distribution rate or that the rate will be sustainable in the future.

The Fund generally distributes each year all of its net investment income and net short-term capital gains. In addition, at least annually, the Fund generally distributes net realized long-term capital gains not previously distributed, if any. The Fund may distribute less than the entire amount of net investment income earned in a particular period. The undistributed net investment income would be available to supplement future distributions. As a result, the distributions paid by the Fund for any particular monthly period may be more or less than the amount of net investment income actually earned by the Fund during the period.

The tax treatment and characterization of the Fund’s distributions may vary significantly from time to time because of the varied nature of the Fund’s investments.

To the extent required by the 1940 Act and other applicable laws, absent an exemption, a notice will accompany each monthly distribution with respect to the estimated source (as between net income, gains or other capital source) of the distribution made. If the Fund estimates that a portion of one of its dividend distributions may be comprised of amounts from sources other than net income, in accordance with its policies and good accounting practices, the Fund will notify shareholders of record of the estimated composition of such distribution through a notice required by Section 19 of the 1940 Act (a “Section 19 Notice”). For these purposes, the Fund estimates the source or sources from which a distribution is paid, to the close of the period as of which it is paid, in reference to its internal accounting records and related accounting practices. If, based on such accounting records and practices, it is estimated that a particular distribution does not include capital gains or paid-in surplus or other capital sources, a Section 19 Notice generally would not be issued. It is important to note that differences exist between the Fund’s daily internal accounting records and practices, the Fund’s financial statements presented in accordance with U.S. GAAP, and recordkeeping practices under income tax regulations. For instance, the Fund’s internal accounting records and practices may take into account, among other factors, tax-related characteristics of certain sources of distributions that differ from treatment under U.S. GAAP. Examples of such differences may include, among others, the treatment of paydowns on mortgage-backed securities purchased at a discount and periodic payments under interest rate swap contracts.

Accordingly, among other consequences, it is possible that the Fund may not issue a Section 19 Notice in situations where the Fund’s financial statements prepared later and in accordance with U.S. GAAP and/or the final tax character of those distributions might later report that the sources of those distributions included capital gains and/or a return of capital.

The tax characterization of the Fund’s distributions made in a taxable year cannot finally be determined until at or after the end of such taxable year. As a result, there is a possibility that the Fund may make total distributions during a taxable year in an amount that exceeds the Fund’s net investment income and net realized capital gains (including as reduced by any capital loss carry-forwards) for the relevant year. For example, the Fund may distribute amounts early in the year that are derived from short-term capital gains, but incur net short-term capital losses later in the year, thereby offsetting short-term capital gains out of which the Fund has already made distributions. In such a situation, the amount by which the Fund’s total distributions exceed net investment income and net realized capital gains would generally be treated as a tax-free return of capital up to the amount of a shareholder’s tax basis in his or her Common Shares, with any amounts exceeding such basis treated as gain from the sale of Common Shares. In general terms, a return of capital would occur where the Fund distribution (or portion thereof) represents a return of a portion of your investment, rather than net income or capital gains generated from your investment during a particular period. Although return of capital distributions are not taxable, such distributions would reduce the basis of a shareholder’s Common Shares and therefore may increase a shareholder’s capital gains, or decrease a shareholder’s capital loss, upon a sale of Common Shares, thereby potentially increasing a shareholder’s tax liability. The Fund will prepare and make available to shareholders detailed tax information with respect to the Fund’s distributions annually. See “Tax Matters.”

The 1940 Act currently limits the number of times the Fund may distribute long-term capital gains in any tax year, which may increase the variability of the Fund’s distributions and result in certain distributions being comprised more or less heavily than others of long-term capital gains currently eligible for favorable income tax rates.

Unless a Common Shareholder elects to receive distributions in cash, all distributions of Common Shareholders whose shares are registered with the plan agent will be automatically reinvested in additional Common Shares of the Fund under the Fund’s Dividend Reinvestment Plan. For more information on the Fund’s dividends and distributions, see “Distributions” and “Dividend Reinvestment Plan.”

Custodian and Transfer Agent

State Street Bank and Trust Company serves as custodian of the Fund’s assets and also provides certain fund accounting and sub-administrative services to the Investment Manager on behalf of the Fund. American Stock Transfer & Trust Company, LLC serves as the Fund’s transfer agent and dividend disbursement agent. See “Custodian and Transfer Agent.”

State Street Bank and Trust Company serves as custodian of assets held by the Fund’s Subsidiaries.

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PIMCO Dynamic Income Fund

Listing

The Fund’s outstanding Common Shares are listed on the NYSE under the trading or “ticker” symbol PDI, as will be the Common Shares offered in this prospectus, subject to notice of issuance.

Market Price of Shares

Shares of closed-end investment companies frequently trade at prices lower than NAV. Shares of closed-end investment companies have during some periods traded at prices higher than NAV and during other periods traded at prices lower than NAV. The Fund cannot assure you that Common Shares will trade at a price equal to or higher than NAV in the future. Proceeds from the sale of Common Shares of an offering will be reduced by any sales load and/or commissions and the amount of offering expenses paid or reimbursed by the Fund. The Fund (and not PIMCO) bears all offering expenses. See “Use of Proceeds.” In addition to NAV, market price may be affected by factors relating to the Fund such as dividend levels and stability (which will in turn be affected by Fund expenses, including the costs of any leverage used by the Fund, levels of interest payments by the Fund’s portfolio holdings, levels of appreciation/depreciation of the Fund’s portfolio holdings, regulation affecting the timing and character of Fund distributions and other factors), portfolio credit quality, liquidity, call protection, market supply and demand and similar factors relating to the Fund’s portfolio holdings. See “Use of Leverage,” “Principal Risks of the Fund,” “Description of Shares” and “Repurchase of Common Shares; Conversion to Open-End Fund” in this prospectus, and see “Repurchase of Common Shares; Conversion to Open-End Fund” in the Statement of Additional Information. The Common Shares are designed for long-term investors and should not be treated as trading vehicles.

Principal Risks of the Fund

The following is a summary of the principal risks associated with an investment in Common Shares of the Fund. Investors should also refer to “Principal Risks of the Fund” in this prospectus and “Investment Objectives and Policies” in the Statement of Additional Information for a more detailed explanation of these and other risks associated with investing in the Fund.

Market Discount Risk

The price of the Fund’s Common Shares will fluctuate with market conditions and other factors. If you sell your Common Shares, the price received may be more or less than your original investment. The Common Shares are designed for long-term investors and should not be treated as trading vehicles. Shares of closed-end management investment companies frequently trade at a discount from their NAV. The Common Shares may trade at a price that is less than the offering price for Common Shares issued pursuant to an offering. This risk may be greater for investors who sell their Common Shares relatively shortly after completion of an offering. The sale of Common Shares by the Fund (or the perception that such sales may occur), particularly if sold at a discount to the then current market price of the Common Shares, may have an adverse effect on the market price of the Common Shares.

Market Risk

The market price of securities owned by the Fund may go up or down, sometimes rapidly or unpredictably. Securities may decline in value due to factors affecting securities markets generally or particular industries represented in the securities markets. The value of a security may decline due to general market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates, adverse changes to credit markets or adverse investor sentiment generally. The value of a security may also decline due to factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry. During a general downturn in the securities markets, multiple asset classes may decline in value simultaneously. Equity securities generally have greater price volatility than fixed income securities. Credit ratings downgrades may also negatively affect securities held by the Fund. Even when markets perform well, there is no assurance that the investments held by the Fund will increase in value along with the broader market.

In addition, market risk includes the risk that geopolitical and other events will disrupt the economy on a national or global level. For instance, war, terrorism, market manipulation, government defaults, government shutdowns, political changes or diplomatic developments, public health emergencies (such as the spread of infectious diseases, pandemics and epidemics) and natural/environmental disasters can all negatively impact the securities markets, which could case the Fund to lose value. These events could reduce consumer demand or economic output, result in market closures, travel restrictions or quarantines, and significantly adversely impact the economy. The current contentious domestic political environment, as well as political and diplomatic events within the United States and abroad, such as presidential elections in the United States. or abroad or the U.S. government’s inability at times to agree on a long-term budget and deficit reduction plan, has in the past resulted, and may in the future result, in a government shutdown or otherwise adversely affect the U.S. regulatory landscape, the general market environment and/or investor sentiment, which could have an adverse impact on the Fund’s investments and operations. Additional and/ or prolonged U.S. federal government shutdowns may affect investor and consumer confidence and may adversely impact financial markets and the broader economy, perhaps suddenly and to a significant degree. Governmental and quasi-governmental authorities and regulators throughout the world have previously responded to serious economic disruptions with a variety of significant fiscal and monetary policy changes, including but not limited to, direct capital infusions into companies, new monetary programs and dramatically lower interest rates. An unexpected or sudden reversal of these policies, or the ineffectiveness of these policies, could increase volatility in securities markets, which could adversely affect the Fund’s investments. Any market disruptions could also prevent the Fund from executing advantageous investment decisions in a timely manner. Funds that have focused their investments in a region enduring

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Base Prospectus

geopolitical market disruption will face higher risks of loss. Thus, investors should closely monitor current market conditions to determine whether the Fund meets their individual financial needs and tolerance for risk.

Recently, there have been signs of inflationary price movements. As such, fixed income securities markets may experience heightened levels of interest rate, volatility and liquidity risk.Any interest rate increases in the future could cause the value of any fund, such as the Fund, that invests in fixed income securities to decrease.

Asset Allocation Risk

The Fund’s investment performance depends upon how its assets are allocated and reallocated. A principal risk of investing in the Fund is that PIMCO may make less than optimal or poor asset allocation decisions. PIMCO employs an active approach to allocation among multiple fixed- income sectors, but there is no guarantee that such allocation techniques will produce the desired results. It is possible that PIMCO will focus on an investment that performs poorly or underperforms other investments under various market conditions. You could lose money on your investment in the Fund as a result of these allocation decisions.

Management Risk

The Fund is subject to management risk because it is an actively managed investment portfolio. PIMCO and each individual portfolio manager will apply investment techniques and risk analysis in making investment decisions for the Fund, but there can be no guarantee that these decisions will produce the desired results. Certain securities or other instruments in which the Fund seeks to invest may not be available in the quantities desired. In addition, regulatory restrictions, actual or potential conflicts of interest or other considerations may cause PIMCO to restrict or prohibit participation in certain investments. In such circumstances, PIMCO or the individual portfolio managers may determine to purchase other securities or instruments as substitutes. Such substitute securities or instruments may not perform as intended, which could result in losses to the Fund. The Fund is also subject to the risk that deficiencies in the internal systems or controls of PIMCO or another service provider will cause losses for the Fund or hinder Fund operations. For example, trading delays or errors (both human and systemic) could prevent the Fund from purchasing a security expected to appreciate in value. To the extent the Fund employs strategies targeting perceived pricing inefficiencies, arbitrage strategies or similar strategies, it is subject to the risk that the pricing or valuation of the securities and instruments involved in such strategies may change unexpectedly, which may result in reduced returns or losses to the Fund. Additionally, actual or potential conflicts of interest, legislative, regulatory, or tax restrictions, policies or developments may affect the investment techniques available to PIMCO and each individual portfolio manager in connection with managing the Fund and may also adversely affect the ability of the Fund to achieve its investment objectives. There also can be no assurance that all of the personnel of PIMCO will continue to be associated with PIMCO for any length of time. The loss of the services of one or more key employees of PIMCO could have an adverse impact on the Fund’s ability to realize its investment objectives.

In addition, the Fund may rely on various third-party sources to calculate its NAV. As a result, the Fund is subject to certain operational risks associated with reliance on service providers and service providers’ data sources. In particular, errors or systems failures and other technological issues may adversely impact the Fund’s calculations of its NAV, and such NAV calculation issues may result in inaccurately calculated NAV, delays in NAV calculation and/or the inability to calculate NAV over extended periods. The Fund may be unable to recover any losses associated with such failures.

Issuer Risk

The value of a security may decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods or services, as well as the historical and prospective earnings of the issuer and the value of its assets. A change in the financial condition of a single issuer may affect securities markets as a whole. These risks can apply to the Common Shares issued by the Fund and to the issuers of securities and other instruments in which the Fund invests.

Interest Rate Risk

Interest rate risk is the risk that fixed income securities and other instruments in the Fund’s portfolio will decline in value because of a change in interest rates. Interest rate changes can be sudden and unpredictable, and the Fund may lose money as a result of movements in interest rates.

A wide variety of factors can cause interest rates or yields of U.S. Treasury securities (or yields of other types of bonds) to rise (e.g., central bank monetary policies, inflation rates, general economic conditions). Recently, there have been signs of inflationary price movements. As such, fixed income securities markets may experience heightened levels of interest rate, volatility and liquidity risk.

Rising interest rates may result in periods of volatility and a decline in value of the Fund’s fixed income investments.

Credit Risk

The Fund could lose money if the issuer or guarantor of a fixed income security, or the counterparty to a derivatives contract, repurchase agreement or a loan of portfolio securities is unable or unwilling, or is perceived as unable or unwilling, to make timely principal and/or interest payments or to otherwise honor its obligations. The downgrade of the credit of a security held by the Fund may decrease its value. Measures such as average credit quality may not accurately reflect the true credit risk of the Fund. This is especially the case if the Fund consists of securities with widely varying credit ratings. This risk is greater to the extent the Fund uses leverage or derivatives in connection with the management of the Fund.

Mortgage-Related and Other Asset-Backed Instruments Risk

Generally, rising interest rates tend to extend the duration of fixed rate mortgage-related assets, making them more sensitive to changes in interest rates. As a result, in a period of rising interest rates, the Fund

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PIMCO Dynamic Income Fund

may exhibit additional volatility since individual mortgage holders are less likely to exercise prepayment options, thereby putting additional downward pressure on the value of these securities and potentially causing the Fund to lose money. The Fund’s investments in other asset-backed instruments are subject to risks similar to those associated with mortgage-related assets, as well as additional risks associated with the nature of the assets and the servicing of those assets. Payment of principal and interest on asset-backed instruments may be largely dependent upon the cash flows generated by the assets backing the instruments, and asset-backed instruments may not have the benefit of any security interest in the related assets.

The Fund may also invest in the residual or equity tranches of mortgage-related and other asset-backed instruments, which may be referred to as subordinate mortgage-backed or asset-backed instruments and interest-only mortgage-backed or asset-backed instruments. The Fund expects that investments in subordinate mortgage-backed and other asset-backed instruments will be subject to risks arising from delinquencies and foreclosures, thereby exposing its investment portfolio to potential losses. Subordinate securities of mortgage-backed and other asset-backed instruments are also subject to greater credit risk than those mortgage-backed or other asset-backed instruments that are more highly rated.

The mortgage markets in the United States and in various foreign countries have experienced extreme difficulties in the past that adversely affected the performance and market value of certain mortgage-related investments. Delinquencies and losses on residential and commercial mortgage loans (especially subprime and second-lien mortgage loans) may increase, and a decline in or flattening of housing and other real property values may exacerbate such delinquencies and losses. In addition, reduced investor demand for mortgage loans and mortgage-related securities and increased investor yield requirements have caused limited liquidity in the secondary market for mortgage-related securities, which can adversely affect the market value of mortgage-related securities. It is possible that such limited liquidity in such secondary markets could continue or worsen.

Mortgage-Related Derivative Instruments Risk

Mortgage-related derivative instruments involve risks associated with mortgage-related and other asset-backed instruments, privately-issued mortgage-related securities, the mortgage market, the real estate industry, derivatives and credit default swaps. See “Mortgage-Related and Other Asset-Backed Instruments Risk,” “Privately-Issued Mortgage-Related Securities Risk,” “Derivatives Risk,” and “Credit Default Swaps Risk.”

Privately-Issued Mortgage-Related Securities Risk

There are no direct or indirect government or agency guarantees of payments in pools created by non-governmental issuers. Privately-issued mortgage-related securities are also not subject to the same underwriting requirements for the underlying mortgages that are applicable to those mortgage-related securities that have a government or government-sponsored entity guarantee.

Privately-issued mortgage-related securities are not traded on an exchange and there may be a limited market for the securities, especially when there is a perceived weakness in the mortgage and real estate market sectors. Without an active trading market, mortgage-related securities held in a Fund’s portfolio may be particularly difficult to value because of the complexities involved in assessing the value of the underlying mortgage loans. Privately-issued mortgage-related securities are not traded on an exchange and there may be a limited market for the securities, especially when there is a perceived weakness in the mortgage and real estate market sectors. Without an active trading market, mortgage-related securities held in the Fund’s portfolio may be particularly difficult to value because of the complexities involved in assessing the value of the underlying mortgage loans.

High Yield Securities Risk

To the extent that the Fund invests in high yield securities and unrated securities of similar credit quality (commonly known as “high yield securities” or “junk bonds”), the Fund will be subject to greater levels of credit risk, call risk and liquidity risk than funds that do not invest in such securities, which could have a negative effect on the NAV and market price of the Fund’s Common Shares or Common Share dividends. These securities are considered predominantly speculative with respect to an issuer’s continuing ability to make principal and interest payments, and may be more volatile than other types of securities. An economic downturn or individual corporate developments could adversely affect the market for these securities and reduce the Fund’s ability to sell these securities at an advantageous time or price. The Fund may purchase distressed securities that are in default or the issuers of which are in bankruptcy, which involve heightened risks.

In general, lower rated debt securities carry a greater degree of risk that the issuer will lose its ability to make interest and principal payments, which could have a negative effect on the NAV and market price of the Fund’s Common Shares or Common Share dividends. Securities of below investment grade quality are regarded as having predominantly speculative characteristics with respect to capacity to pay interest and repay principal, and are commonly referred to as “high yield” securities or “junk bonds.” High yield securities involve a greater risk of default and their prices are generally more volatile and sensitive to actual or perceived negative developments. An economic downturn could severely affect the ability of issuers (particularly those that are highly leveraged) to service or repay their debt obligations. The Fund may purchase stressed or distressed securities that are in default or the issuers of which are in bankruptcy, which involve heightened risks. Lower-rated securities are generally less liquid than higher-rated securities, which may have an adverse effect on the Fund’s ability to dispose of a particular security. To the extent the Fund focuses on below investment grade debt obligations, PIMCO’s capabilities in analyzing credit quality and associated risks will be particularly important, and there can be no assurance that PIMCO will be successful in this regard. Due to the risks involved in investing in high yield securities, an investment in the Fund should be considered speculative.

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Base Prospectus

The Fund’s credit quality policies apply only at the time a security is purchased, and the Fund is not required to dispose of a security in the event that a rating agency or PIMCO downgrades its assessment of the credit characteristics of a particular issue. Analysis of creditworthiness may be more complex for issuers of high yield securities than for issuers of higher quality debt securities.

Distressed and Defaulted Securities Risk

Investments in the securities of financially distressed issuers involve substantial risks, including the risk of default. Such investments may be in default at the time of investment. In addition, these securities may fluctuate more in price, and are typically less liquid. The Fund also will be subject to significant uncertainty as to when, and in what manner, and for what value obligations evidenced by securities of financially distressed issuers will eventually be satisfied. Defaulted obligations might be repaid only after lengthy workout or bankruptcy proceedings, during which the issuer might not make any interest or other payments. In any such proceeding relating to a defaulted obligation, the Fund may lose its entire investment or may be required to accept cash or securities with a value substantially less than its original investment. Moreover, any securities received by the Fund upon completion of a workout or bankruptcy proceeding may be less liquid, speculative or restricted as to resale. Similarly, if the Fund participates in negotiations with respect to any exchange offer or plan of reorganization with respect to the securities of a distressed issuer, the Fund may be restricted from disposing of such securities. To the extent that the Fund becomes involved in such proceedings, the Fund may have a more active participation in the affairs of the issuer than that assumed generally by an investor. The Fund may incur additional expenses to the extent it is required to seek recovery upon a default in the payment of principal or interest on its portfolio holdings.

Also among the risks inherent in investments in a troubled issuer is that it frequently may be difficult to obtain information as to the true financial condition of such issuer. PIMCO’s judgments about the credit quality of a financially distressed issuer and the relative value of its securities may prove to be wrong.

Inflation-Indexed Security Risk

Inflation-indexed debt securities are subject to the effects of changes in market interest rates caused by factors other than inflation (real interest rates). In general, the value of an inflation-indexed security, including Treasury Inflation-Protected Securities (“TIPS”), tends to decrease when real interest rates increase and can increase when real interest rates decrease. Thus generally, during periods of rising inflation, the value of inflation-indexed securities will tend to increase and during periods of deflation, their value will tend to decrease. Interest payments on inflation-indexed securities are unpredictable and will fluctuate as the principal and interest are adjusted for inflation. There can be no assurance that the inflation index used (i.e., the Consumer Price Index (“CPI”)) will accurately measure the real rate of inflation. Increases in the principal value of TIPS due to inflation are considered taxable ordinary income. Any increase in the principal amount of an inflation-indexed debt security will be considered taxable ordinary

income, even though the Fund will not receive the principal until maturity. Additionally, a CPI swap can potentially lose value if the realized rate of inflation over the life of the swap is less than the fixed market implied inflation rate (fixed breakeven rate) that the investor agrees to pay at the initiation of the swap. With municipal inflation-indexed securities, the inflation adjustment is integrated into the coupon payment, which is federally tax-exempt (and may be state tax-exempt). For municipal inflation-indexed securities, there is no adjustment to the principal value. Because municipal inflation-indexed securities are a small component of the municipal bond market, they may be less liquid than conventional municipal bonds.

Senior Debt Risk

The Fund will be subject to greater levels of credit risk than funds that do not invest in below investment grade senior debt. The Fund may also be subject to greater levels of liquidity risk than funds that do not invest in senior debt. Restrictions on transfers in loan agreements, a lack of publicly available information and other factors may, in certain instances, make senior debt more difficult to sell at an advantageous time or price than other types of securities or instruments. Additionally, if the issuer of senior debt prepays, the Fund will have to consider reinvesting the proceeds in other senior debt or similar instruments that may pay lower interest rates.

Loans and Other Indebtedness; Loan Participations and Assignments Risk

Loan interests may take the form of (i) direct interests acquired during a primary distribution, (ii) loans originated by the Fund or (iii) assignments of, novations of or participations in all or a portion of a loan acquired in secondary markets. In addition to credit risk and interest rate risk, the Fund’s exposure to loan interests may be subject to additional risks. For example, purchasers of loans and other forms of direct indebtedness depend primarily upon the creditworthiness of the borrower for payment of principal and interest. Loans are subject to the risk that scheduled interest or principal payments will not be made in a timely manner or at all, either of which may adversely affect the values of the loan. If the Fund does not receive scheduled interest or principal payments on such indebtedness, the Fund’s share price and yield could be adversely affected. Loans that are fully secured offer the Fund more protection that an unsecured loan in the event of non-payment of scheduled interest or principal. However, the collateral underlying a loan may be unavailable or insufficient to satisfy a borrower’s obligation, and the Fund could become part owner of any collateral if a loan is foreclosed, subjecting the Fund to costs associated with owning and disposing of the collateral.

Investments in loans through a purchase of a loan, loan origination or a direct assignment of a financial institution’s interests with respect to a loan may involve additional risks to the Fund. For example, if a loan is foreclosed, the Fund could become owner, in whole or in part, of any collateral, which could include, among other assets, real estate or other real or personal property, and would bear the costs and liabilities associated with owning and holding or disposing of the collateral. The purchaser of an assignment typically succeeds to all the rights and

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PIMCO Dynamic Income Fund

obligations under the loan agreement with the same rights and obligations as the assigning lender. Assignments may, however, be arranged through private negotiations between potential assignees and potential assignors, and the rights and obligations acquired by the purchaser of an assignment may differ from, and be more limited than, those held by the assigning lender.

In connection with purchasing loan participations, the Fund generally will have no right to enforce compliance by the borrower with the terms of the loan agreement relating to the loan, nor any rights of set-off against the borrower, and the Fund may not directly benefit from any collateral supporting the loan in which it has purchased the loan participation. As a result, the Fund will be subject to the credit risk of both the borrower and the lender that is selling the participation. In the event of the insolvency of the lender selling a participation, the Fund may be treated as a general creditor of the lender and may not benefit from any set-off between the lender and the borrower. Certain loan participations may be structured in a manner designed to prevent purchasers of participations from being subject to the credit risk of the lender, but even under such a structure, in the event of the lender’s insolvency, the lender’s servicing of the participation may be delayed and the assignability of the participation impaired.

The Fund may have difficulty disposing of loans and loan participations because to do so it will have to assign or sell such securities to a third party. Because there is no liquid market for many such securities, the Fund anticipates that such securities could be sold only to a limited number of institutional investors. The lack of a liquid secondary market may have an adverse impact on the value of such securities and the Fund’s ability to dispose of particular loans and loan participations when that would be desirable, including in response to a specific economic event such as a deterioration in the creditworthiness of the borrower. The lack of a liquid secondary market for loans and loan participations also may make it more difficult for the Fund to assign a value to these securities for purposes of valuing the Fund’s portfolio. Investments in loans may include participations in bridge loans, which are loans taken out by borrowers for a short period (typically less than one year) pending arrangement of more permanent financing through, for example, the issuance of bonds, frequently high yield bonds issued for the purpose of acquisitions.

To the extent the Fund invests in loans, including bank loans, the residual or equity tranches of mortgage-related and other asset-backed securities, which may be referred to as subordinate mortgage-backed or asset-backed securities and interest-only mortgage-backed or asset-backed securities, and other investments, the Fund may be subject to greater levels of credit risk, call risk, settlement risk and liquidity risk. These instruments are considered predominantly speculative with respect to an issuer’s continuing ability to make principal and interest payments and may be more volatile than other types of securities. The Fund may also be subject to greater levels of liquidity risk than funds that do not invest in loans. In addition, the loans in which the Fund invests may not be listed on any exchange and a secondary market for such loans may be comparatively illiquid relative to markets for other more liquid fixed income securities. Consequently, transactions in loans

may involve greater costs than transactions in more actively traded securities. In connection with certain loan transactions, transaction costs that are borne by the Fund may include the expenses of third parties that are retained to assist with reviewing and conducting diligence, negotiating, structuring and servicing a loan transaction, and/or providing other services in connection therewith. Furthermore, the Fund may incur such costs in connection with loan transactions that are pursued by the Fund but not ultimately consummated (so-called “broken deal costs”). Restrictions on transfers in loan agreements, a lack of publicly-available information, irregular trading activity and wide bid/ask spreads, among other factors, may, in certain circumstances, make loans more difficult to sell at an advantageous time or price than other types of securities or instruments. These factors may result in the Fund being unable to realize full value for the loans and/or may result in the Fund not receiving the proceeds from a sale of a loan for an extended period after such sale, each of which could result in losses to the Fund. Some loans may have extended trade settlement periods, including settlement periods of greater than seven days, which may result in cash not being immediately available to the Fund. If an issuer of a loan prepays or redeems the loan prior to maturity, the Fund may have to reinvest the proceeds in other loans or similar instruments that may pay lower interest rates. Because of the risks involved in investing in loans, an investment in the Fund should be considered speculative.

The Fund’s investments in subordinated and unsecured loans generally are subject to similar risks as those associated with investments in secured loans. Subordinated or unsecured loans are lower in priority of payment to secured loans and are subject to the additional risk that the cash flow of the borrower and property securing the loan or debt, if any, may be insufficient to meet scheduled payments after giving effect to the senior secured obligations of the borrower. This risk is generally higher for subordinated unsecured loans or debt, which are not backed by a security interest in any specific collateral. Subordinated and unsecured loans generally have greater price volatility than secured loans and may be less liquid. There is also a possibility that originators will not be able to sell participations in subordinated or unsecured loans, which would create greater credit risk exposure for the holders of such loans. Subordinate and unsecured loans share the same risks as other below investment grade securities.

There may be less readily available information about most loans and the underlying borrowers than is the case for many other types of securities. Loans may be issued by companies that are not subject to SEC reporting requirements and therefore may not be required to file reports with the SEC or may file reports that are not required to comply with SEC form requirements. In addition, such companies may be subject to a less stringent liability disclosure regime than companies subject to SEC reporting requirements. Loans may not be considered “securities,” and purchasers, such as the Fund, therefore may not be entitled to rely on the anti-fraud protections of the federal securities laws. Because there is limited public information available regarding loan investments, the Fund is particularly dependent on the analytical abilities of the Fund’s portfolio managers.

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Base Prospectus

Economic exposure to loan interests through the use of derivative transactions may involve greater risks than if the Fund had invested in the loan interest directly during a primary distribution through direct originations or through assignments of, novations of or participations in a loan acquired in secondary markets since, in addition to the risks described above, certain derivative transactions may be subject to leverage risk and greater illiquidity risk, counterparty risk, valuation risk and other risks.

Loan Origination Risk

The Fund may seek to originate loans, including, without limitation, residential and/or commercial real estate or mortgage-related loans, consumer loans or other types of loans, which may be in the form of whole loans, secured and unsecured notes, senior and second lien loans, mezzanine loans or similar investments. The Fund may originate loans to corporations and/or other legal entities and individuals, including foreign (non-U.S. and emerging market) entities and individuals. Such borrowers may have credit ratings that are determined by one or more NRSROs or PIMCO to be below investment grade. The Fund may subsequently offer such investments for sale to third parties; provided, that there is no assurance that the Fund will complete the sale of such an investment. If the Fund is unable to sell, assign or successfully close transactions for the loans that it originates, the Fund will be forced to hold its interest in such loans for an indeterminate period of time. This could result in the Fund’s investments having high exposure to certain borrowers. The Fund will be responsible for the expenses associated with originating a loan (whether or not consummated). This may include significant legal and due diligence expenses, which will be indirectly borne by the Fund and Common Shareholders. Loan origination and servicing companies are routinely involved in legal proceedings concerning matters that arise in the ordinary course of their business. In addition, a number of participants in the loan origination and servicing industry (including control persons of industry participants) have been the subject of regulatory actions by state regulators, including state attorneys general, and by the federal government.

Governmental investigations, examinations or regulatory actions, or private lawsuits, including purported class action lawsuits, may adversely affect such companies’ financial results. To the extent the Fund engages in origination and/or servicing directly, or has a financial interest in, or is otherwise affiliated with, an origination or servicing company, the Fund will be subject to enhanced risks of litigation, regulatory actions and other proceedings. As a result, the Fund may be required to pay legal fees, settlement costs, damages, penalties or other charges, any or all of which could materially adversely affect the Fund and its holdings.

“Covenant-lite” Obligations Risk

Covenant-lite obligations contain fewer maintenance covenants than other obligations, or no maintenance covenants, and may not include terms that allow the lender to monitor the performance of the borrower and declare a default if certain criteria are breached. Covenant-lite loans may carry more risk than traditional loans as they allow individuals and corporations to engage in activities that would

otherwise be difficult or impossible under a covenant-heavy loan agreement. In the event of default, covenant-lite loans may exhibit diminished recovery values as the lender may not have the opportunity to negotiate with the borrower prior to default.

Subprime Risk

Loans, and debt instruments collateralized by loans (including Alt Lending ABS), acquired by the Fund may be subprime in quality, or may become subprime in quality. Although there is no specific legal or market definition of “subprime,” subprime loans are generally understood to refer to loans made to borrowers that display poor credit histories and other characteristics that correlate with a higher default risk. Accordingly, subprime loans, and debt instruments secured by such loans (including Alt Lending ABS), have speculative characteristics and are subject to heightened risks, including the risk of nonpayment of interest or repayment of principal, and the risks associated with investments in high yield securities. In addition, these instruments could be subject to increased regulatory scrutiny. The Fund is not restricted by any particular borrower credit criteria when acquiring loans or debt instruments collateralized by loans.

Privacy and Data Security Risk

The Gramm-Leach-Bliley Act (“GLBA”) and other laws limit the disclosure of certain non-public personal information about a consumer to non- affiliated third parties and require financial institutions to disclose certain privacy policies and practices with respect to information sharing with both affiliates and non- affiliated third parties. Many states and a number of non-U.S. jurisdictions have enacted privacy and data security laws requiring safeguards on the privacy and security of consumers’ personally identifiable information. Other laws deal with obligations to safeguard and dispose of private information in a manner designed to avoid its dissemination. Privacy rules adopted by the U.S. Federal Trade Commission and SEC implement GLBA and other requirements and govern the disclosure of consumer financial information by certain financial institutions, ranging from banks to private investment funds. U.S. platforms following certain models generally are required to have privacy policies that conform to these GLBA and other requirements. In addition, such platforms typically have policies and procedures intended to maintain platform participants’ personal information securely and dispose of it properly.

The Fund generally does not intend to obtain or hold borrowers’ non-public personal information, and the Fund has implemented procedures designed to prevent the disclosure of borrowers’ non-public personal information to the Fund. However, service providers to the Fund or its Subsidiaries, including their custodians and the platforms acting as loan servicers for the Fund or Subsidiaries, may obtain, hold or process such information. The Fund cannot guarantee the security of non-public personal information in the possession of such a service provider and cannot guarantee that service providers have been and will continue to comply with the GLBA, other data security and privacy laws and any other related regulatory requirements. Violations of GLBA and other laws could subject the Fund to litigation and/or fines, penalties or other regulatory action, which, individually or in the aggregate, could

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have an adverse effect on the Fund. The Fund may also face regulations related to privacy and data security in the other jurisdictions in which the Fund invests.

Platform Risk

The Alt Lending ABS in which the Fund may invest are typically not listed on any securities exchange and not registered under the Securities Act. In addition, the Fund anticipates that these instruments may only be sold to a limited number of investors and may have a limited or non-existent secondary market. Accordingly, the Fund currently expects that certain of the investments it may make in Alt Lending ABS will face heightened levels of liquidity risk. Although currently there is generally no reliable, active secondary market for certain Alt Lending ABS, a secondary market for these Alt Lending ABS may develop. If the Fund purchases Alt Lending ABS on an alternative lending platform, the Fund will have the right to receive principal and interest payments due on loans underlying the Alt Lending ABS only if the platform servicing the loans receives the borrower’s payments on such loans and passes such payments through to the Fund. If a borrower is unable or fails to make payments on a loan for any reason, the Fund may be greatly limited in its ability to recover any outstanding principal or interest due, as (among other reasons) the Fund may not have direct recourse against the borrower or may otherwise be limited in its ability to directly enforce its rights under the loan, whether through the borrower or the platform through which such loan was originated, the loan may be unsecured or under-collateralized and/or it may be impracticable to commence a legal proceeding against the defaulting borrower.

The Fund may have limited knowledge about the underlying loans and is dependent upon the platform for information regarding underlying loans. Although PIMCO may conduct diligence on the platforms, the Fund generally does not have the ability to independently verify the information provided by the platforms, other than payment information regarding loans underlying the Alt Lending ABS owned by the Fund, which the Fund observes directly as payments are received. With respect to Alt Lending ABS that the Fund purchases in the secondary market (i.e., not directly from an alternative lending platform), the Fund may not perform the same level of diligence on such platform or at all. The Fund may not review the particular characteristics of the loans collateralizing an Alt Lending ABS, but rather negotiate in advance with platforms the general criteria of the underlying loans. As a result, the Fund is dependent on the platforms’ ability to collect, verify and provide information to the Fund about each loan and borrower.

The Fund relies on the borrower’s credit information, which is provided by the platforms. However, such information may be out of date, incomplete or inaccurate and may, therefore, not accurately reflect the borrower’s actual creditworthiness. Platforms may not have an obligation to update borrower information, and, therefore, the Fund may not be aware of any impairment in a borrower’s creditworthiness subsequent to the making of a particular loan. The platforms’ credit decisions and scoring models may be based on algorithms that could potentially contain programming or other errors or prove to be ineffective or otherwise flawed. This could adversely affect loan pricing

data and approval processes and could cause loans to be mispriced or misclassified, which could ultimately have a negative impact on the Fund’s performance.

In addition, the underlying loans, in some cases, may be affected by the success of the platforms through which they are facilitated. Therefore, disruptions in the businesses of such platforms may also negatively impact the value of the Fund’s investments. In addition, disruption in the business of a platform could limit or eliminate the ability of the Fund to invest in loans originated by that platform, and therefore the Fund could lose some or all of the benefit of its diligence effort with respect to that platform.

Platforms are for-profit businesses that, as a general matter, generate revenue by collecting fees on funded loans from borrowers and by assessing a loan servicing fee on investors, which may be a fixed annual amount or a percentage of the loan or amounts collected. This business could be disrupted in multiple ways; for example, a platform could file for bankruptcy or a platform might suffer reputational harm from negative publicity about the platform or alternative lending more generally and the loss of investor confidence in the event that a loan facilitated through the platform is not repaid and the investor loses money on its investment. Many platforms and/or their affiliates have incurred operating losses since their inception and may continue to incur net losses in the future, particularly as their businesses grow and they incur additional operating expenses Platforms may also be forced to defend legal action taken by regulators or governmental bodies. Alternative lending is a newer industry operating in an evolving legal environment. Platforms may be subject to risk of litigation alleging violations of law and/or regulations, including, for example, consumer protection laws, whether in the U.S. or in foreign jurisdictions.

Platforms may be unsuccessful in defending against such lawsuits or other actions and, in addition to the costs incurred in fighting any such actions, platforms may be required to pay money in connection with the judgments, settlements or fines or may be forced to modify the terms of its borrower loans, which could cause the platform to realize a loss or receive a lower return on a loan than originally anticipated. Platforms may also be parties to litigation or other legal action in an attempt to protect or enforce their rights or those of affiliates, including intellectual property rights, and may incur similar costs in connection with any such efforts. The Fund’s investments in Alt Lending ABS may expose the Fund to the credit risk of the issuer. Generally, such instruments are unsecured obligations of the issuer; an issuer that becomes subject to bankruptcy proceedings may be unable to make full and timely payments on its obligations to the Fund, even if the payments on the underlying loan or loans continue to be made timely and in full. In addition, when the Fund owns Alt Lending ABS, the Fund and its custodian generally does not have a contractual relationship with, or personally identifiable information regarding, individual borrowers, so the Fund will not be able to enforce underlying loans directly against borrowers and may not be able to appoint an alternative servicing agent in the event that a platform or third-party servicer, as applicable, ceases to service the underlying loans. Therefore, the Fund is more dependent on the platform for servicing than if the Fund had owned whole loans through the

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Base Prospectus

platform. Where such interests are secured, the Fund relies on the platform to perfect the Fund’s security interest. In addition, there may be a delay between the time the Fund commits to purchase an instrument issued by a platform, its affiliate or a special purpose entity sponsored by the platform or its affiliate and the issuance of such instrument and, during such delay, the funds committed to such an investment will not earn interest on the investment nor will they be available for investment in other alternative lending-related instruments, which will reduce the effective rate of return on the investment. The Fund’s investments in Alt Lending ABS may be illiquid.

Risk Retention Investment Risk

The Fund may invest in risk retention tranches of commercial mortgage-backed securities (“CMBS”) or other eligible securitizations, if any (“risk retention tranches”), which are eligible residual interests typically held by the sponsors of such securitizations pursuant to the final rules implementing the credit risk retention requirements of Section 941 of the Dodd-Frank Act (the “U.S. Risk Retention Rules”). In the case of CMBS transactions, for example, the U.S. Risk Retention Rules permit all or a portion of the retained credit risk associated with certain securitizations (i.e., retained risk) to be held by an unaffiliated “third party purchaser,” such as the Fund, if, among other requirements, the third-party purchaser holds its retained interest, unhedged, for at least five years following the closing of the CMBS transaction, after which it is entitled to transfer its interest in the securitization to another person that meets the requirements for a third-party purchaser. Even after the required holding period has expired, due to the generally illiquid nature of such investments, no assurance can be given as to what, if any, exit strategies will ultimately be available for any given position. In addition, there is limited guidance on the application of the final U.S. Risk Retention Rules to specific securitization structures. There can be no assurance that the applicable federal agencies charged with the implementation of the final U.S. Risk Retention Rules (the Federal Deposit Insurance Corporation, the Comptroller of the Currency, the Federal Reserve Board, the SEC, the Department of Housing and Urban Development, and the Federal Housing Finance Agency) could not take positions in the future that differ from the interpretation of such rules taken or embodied in such securitizations, or that the final U.S. Risk Retention Rules will not change.

Furthermore, in situations where the Fund invests in risk retention tranches of securitizations structured by third parties, the Fund may be required to execute one or more letters or other agreements, the exact form and nature of which will vary (each, a “Risk Retention Agreement”) under which it will make certain undertakings designed to ensure such securitization complies with the final U.S. Risk Retention Rules. Such Risk Retention Agreements may include a variety of representations, warranties, covenants and other indemnities, each of which may run to various transaction parties. If the Fund breaches any undertakings in any Risk Retention Agreement, it will be exposed to claims by the other parties thereto, including for any losses incurred as a result of such breach, which could be significant and exceed the value of the Fund’s investments.

Reinvestment Risk

Income from the Fund’s portfolio will decline if and when the Fund invests the proceeds from matured, traded or called debt obligations at market interest rates that are below the portfolio’s current earnings rate.For instance, during periods of declining interest rates, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, forcing the Fund to invest in lower-yielding securities The Fund also may choose to sell higher yielding portfolio securities and to purchase lower yielding securities to achieve greater portfolio diversification, because the portfolio managers believe the current holdings are overvalued or for other investment-related reasons. A decline in income received by the Fund from its investments is likely to have a negative effect on dividend levels and the market price, NAV and/or overall return of the Common Shares.

Securities Lending Risk

For the purpose of achieving income, the Fund may lend its portfolio securities to brokers, dealers, and other financial institutions provided a number of conditions are satisfied, including that the loan is fully collateralized. Please see “Investment Objectives and Policies—Loans of Portfolio Securities” in the Statement of Additional Information for more details. When the Fund lends portfolio securities, its investment performance will continue to reflect changes in the value of the securities loaned, and the Fund will also receive a fee or interest on the collateral. Securities lending involves the risk of loss of rights in the collateral or delay in recovery of the collateral if the borrower fails to return the security loaned or becomes insolvent. The Fund may pay lending fees to a party arranging the loan. Cash collateral received by the Fund in securities lending transactions may be invested in short-term liquid fixed income instruments or in money market or short-term mutual funds, or similar investment vehicles, including affiliated money market or short-term mutual funds. The Fund bears the risk of such investments.

Call Risk

Call risk refers to the possibility that an issuer may exercise its right to redeem a fixed income security earlier than expected. Issuers may call outstanding securities prior to their maturity for a number of reasons. If an issuer calls a security in which the Fund has invested, the Fund may not recoup the full amount of its initial investment and may be forced to reinvest in lower-yielding securities, securities with greater credit risks or securities with other, less favorable features.

Foreign (Non-U.S.) Investment Risk

Foreign (non-U.S.) securities may experience more rapid and extreme changes in value than securities of U.S. companies. The securities markets of many foreign countries are relatively small, with a limited number of companies representing a small number of industries. Additionally, issuers of foreign (non-U.S.) securities are usually not subject to the same degree of regulation as U.S. issuers. Global economies and financial markets are becoming increasingly interconnected, and conditions and events in one country, region or financial market may adversely impact issuers in a different country,

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region or financial market. Also, nationalization, expropriation or confiscatory taxation, currency blockage, political changes or diplomatic developments could adversely affect the Fund’s investments in a foreign country. In the event of nationalization, expropriation or other confiscation, the Fund could lose its entire investment in foreign (non-U.S.) securities. To the extent that the Fund invests a significant portion of its assets in a specific geographic region, the Fund will generally have more exposure to regional economic risks associated with foreign (non-U.S.) investments. Foreign (non-U.S.) securities may also be less liquid and more difficult to value than securities of U.S. issuers.

Emerging Markets Risk

Foreign investment risk may be particularly high to the extent that the Fund invests in securities of issuers based in or doing business in emerging market countries or invests in securities denominated in the currencies of emerging market countries. Investing in securities of issuers based in or doing business in emerging markets entails all of the risks of investing in foreign securities noted above, but to a heightened degree.

Investments in emerging market countries pose a greater degree of systemic risk (i.e., the risk of a cascading collapse of multiple institutions within a country, and even multiple national economies). The inter-relatedness of economic and financial institutions within and among emerging market economies has deepened over the years, with the effect that institutional failures and/or economic difficulties that are of initially limited scope may spread throughout a country, a region or all or most emerging market countries. This may undermine any attempt by the Fund to reduce risk through geographic diversification of its portfolio.

There is also a greater risk that an emerging market government may take action that impedes or prevents the Fund from taking income and/or capital gains earned in the local currency and converting into U.S. dollars (i.e., “repatriating” local currency investments or profits). Certain emerging market countries have sought to maintain foreign exchange reserves and/or address the economic volatility and dislocations caused by the large international capital flows by controlling or restricting the conversion of the local currency into other currencies. This risk tends to become more acute when economic conditions otherwise worsen. There can be no assurance that if the Fund earns income or capital gains in an emerging market currency or PIMCO otherwise seeks to withdraw the Fund’s investments from a given emerging market country, capital controls imposed by such country will not prevent, or cause significant expense or delay in, doing so.

Emerging market countries typically have less established legal, accounting and financial reporting systems than those in more developed markets, which may reduce the scope or quality of financial information available to investors. Governments in emerging market countries are often less stable and more likely to take extra-legal action with respect to companies, industries, assets, or foreign ownership than those in more developed markets. Moreover, it can be more difficult for investors to bring litigation or enforce judgments against issuers in

emerging markets or for U.S. regulators to bring enforcement actions against such issuers. The Fund may also be subject to Emerging Markets Risk if it invests in derivatives or other securities or instruments whose value or return are related to the value or returns of emerging markets securities.

The economy of some emerging markets may be particularly exposed to or affected by a certain industry or sector, and therefore issuers and/or securities of such emerging markets may be more affected by the performance of such industries or sectors.

Currency Risk

Currency risk may be particularly high because the Fund may, at times or in general, have substantial exposure to emerging market currencies, and engage in foreign currency transactions that are economically tied to emerging market countries. These currency transactions may present market, credit, currency, liquidity, legal, political and other risks different from, or greater than, the risks of investing in developed foreign (non-U.S.) currencies or engaging in foreign currency transactions that are economically tied to developed foreign countries. Investments denominated in foreign (non-U.S.) currencies or that trade in, and receive revenues in, foreign (non-U.S.) currencies, derivatives or other investments that provide exposure to foreign (non-U.S.) currencies, are subject to the risk that those currencies will decline in value relative to the U.S. dollar, or, in the case of hedging positions, that the U.S. dollar will decline in value relative to the currency being hedged.

Currency rates in foreign (non-U.S.) countries may fluctuate significantly over short periods of time for a number of reasons, including changes in interest rates, rates of inflation, balance of payments and governmental surpluses or deficits, intervention (or the failure to intervene) by U.S. or foreign (non-U.S.) governments, central banks or supranational entities such as the International Monetary Fund, or by the imposition of currency controls or other political developments in the United States or abroad. These fluctuations may have a significant adverse impact on the value of the Fund’s portfolio and/or the level of Fund distributions made to Common Shareholders. There is no assurance that a hedging strategy, if used, will be successful. Moreover, currency hedging techniques may be unavailable with respect to emerging market currencies. As a result, the Fund’s investments in foreign currency-denominated, and especially emerging market-currency denominated, securities may reduce the returns of the Fund. The local emerging market currencies in which the Fund may be invested from time to time may experience substantially greater volatility against the U.S. dollar than the major convertible currencies of developed countries. Some of the local currencies in which the Fund may invest are neither freely convertible into one of the major currencies nor internationally traded. The local currencies may be convertible into other currencies only inside the relevant emerging market where the limited availability of such other currencies may tend to inflate their values relative to the local currency in question. Such internal exchange markets can therefore be said to be neither liquid nor competitive. In addition, many of the currencies of emerging market countries in which the Fund may invest have experienced steady devaluation relative to freely convertible currencies.

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Base Prospectus

Continuing uncertainty as to the status of the euro and the European Monetary Union (“EMU”) has created significant volatility in currency and financial markets generally. Any partial or complete dissolution of the EMU could have significant adverse effects on currency and financial markets, and on the values of the Fund’s portfolio investments. If one or more EMU countries were to stop using the euro as its primary currency, the Fund’s investments in such countries may be redenominated into a different or newly adopted currency. As a result, the value of those investments could decline significantly and unpredictably. In addition, securities or other investments that are redenominated may be subject to foreign currency risk, liquidity risk and valuation risk to a greater extent than similar investments currently denominated in euros. To the extent a currency used for redenomination purposes is not specified in respect of certain EMU-related investments, or should the euro cease to be used entirely, the currency in which such investments are denominated may be unclear, making such investments particularly difficult to value or dispose of. The Fund may incur additional expenses to the extent it is required to seek judicial or other clarification of the denomination or value of such securities.

There can be no assurance that if the Fund earns income or capital gains in a non-U.S. country or PIMCO otherwise seeks to withdraw the Fund’s investments from a given country, capital controls imposed by such country will not prevent, or cause significant expense in, doing so.

U.S. Government Securities Risk

Certain U.S. government securities, such as U.S. Treasury bills, notes, bonds, and mortgage-related securities guaranteed by the Government National Mortgage Association (“GNMA”), are supported by the full faith and credit of the United States; others, such as those of the Federal Home Loan Banks (“FHLBs”) or the Federal Home Loan Mortgage Corporation (“FHLMC”), are supported by the right of the issuer to borrow from the U.S. Treasury; others, such as those of the Federal National Mortgage Association (“FNMA”), are supported by the discretionary authority of the U.S. government to purchase the agency’s obligations; and still others are supported only by the credit of the agency, instrumentality or corporation. Although legislation has been enacted to support certain government sponsored entities, including the FHLBs, FHLMC and FNMA, there is no assurance that the obligations of such entities will be satisfied in full, or that such obligations will not decrease in value or default. It is difficult, if not impossible, to predict the future political, regulatory or economic changes that could impact the government sponsored entities and the values of their related securities or obligations. In addition, certain governmental entities, including FNMA and FHLMC, have been subject to regulatory scrutiny regarding their accounting policies and practices and other concerns that may result in legislation, changes in regulatory oversight and/or other consequences that could adversely affect the credit quality, availability or investment character of securities issued by these entities. Yields available from U.S. government debt securities are generally lower than the yields available from other debt securities. The values of U.S. government securities change as interest rates fluctuate.

Convertible Securities Risk

The market values of convertible securities may decline as interest rates increase and, conversely, may increase as interest rates decline. A convertible security’s market value, however, tends to reflect the market price of the common stock of the issuing company when that stock price approaches or is greater than the convertible security’s “conversion price.” The conversion price is defined as the predetermined price at which the convertible security could be exchanged for the associated stock. As the market price of the underlying common stock declines, the price of the convertible security tends to be influenced more by the yield of the convertible security. Thus, it may not decline in price to the same extent as the underlying common stock. In the event of a liquidation of the issuing company, holders of convertible securities may be paid before the company’s common stockholders but after holders of any senior debt obligations of the company. Consequently, the issuer’s convertible securities generally entail less risk than its common stock but more risk than its other debt obligations. Convertible securities are often rated below investment grade or not rated.

Synthetic Convertible Securities Risk

The values of synthetic convertible securities will respond differently to market fluctuations than a traditional convertible security because a synthetic convertible is composed of two or more separate securities or instruments, (such as a debt security and a warrant or option to purchase another security), each with its own market value. Synthetic convertible securities are also subject to the risks associated with derivatives. In addition, if the value of the underlying common stock or the level of the index involved in the convertible element falls below the strike price of the warrant or option, the warrant or option may lose all value.

Contingent Convertible Securities Risk

The risks of investing in CoCos include, without limitation, the risk that interest payments will be cancelled by the issuer or a regulatory authority, the risk of ranking junior to other creditors in the event of a liquidation or other bankruptcy-related event as a result of holding subordinated debt, the risk of the Fund’s investment becoming further subordinated as a result of conversion from debt to equity, the risk that the principal amount due can be written down to a lesser amount, and the general risks applicable to fixed income investments, including interest rate risk, credit risk, market risk and liquidity risk, any of which could result in losses to the Fund. CoCos may experience a loss absorption mechanism trigger event, which would likely be the result of, or related to, the deterioration of the issuer’s financial condition (e.g., a decrease in the issuer’s capital ratio) and status as a going concern. In such a case, with respect to CoCos that provide for conversion into common stock upon the occurrence of the trigger event, the market price of the issuer’s common stock received by the Fund will have likely declined, perhaps substantially, and may continue to decline, which may adversely affect the Fund’s NAV.

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PIMCO Dynamic Income Fund

Real Estate Risk

To the extent that the Fund invests in real estate investments, including investments in equity or debt securities issued by private and public REITs, real estate operating companies (‘REOCs”), private or public real estate-related loans and real estate-linked derivative instruments, it will be subject to the risks associated with owning real estate and with the real estate industry generally. These risks include, but are not limited to: the burdens of ownership of real property; general and local economic conditions(such as an oversupply of space or a reduction in demand for space); the supply and demand for properties (including competition based on rental rates); energy and supply shortages; fluctuations in average occupancy and room rates; the attractiveness, type and location of the properties and changes in the relative popularity of commercial properties as an investment; the financial condition and resources of tenants, buyers and sellers of properties; increased mortgage defaults; the quality of maintenance, insurance and management services; changes in the availability of debt financing which may render the sale or refinancing of properties difficult or impracticable; changes in building, environmental and other laws and/or regulations (including those governing usage and improvements), fiscal policies and zoning laws; changes in real property tax rates; changes in interest rates and the availability of mortgage funds which may render the sale or refinancing of properties difficult or impracticable; changes in operating costs and expenses; energy and supply shortages; uninsured losses or delays from casualties or condemnation; negative developments in the economy that depress travel or leasing activity; environmental liabilities; contingent liabilities on disposition of assets; uninsured or uninsurable casualties; acts of God, including earthquakes, hurricanes and other natural disasters; social unrest and civil disturbances, epidemics, pandemics or other public crises; terrorist attacks and war; risks and operating problems arising out of the presence of certain construction materials, structural or property level latent defects, work stoppages, shortages of labor, strikes, union relations and contracts, fluctuating prices and supply of labor and/or other labor-related factor; and other factors which are beyond the control of PIMCO and its affiliates.

In addition, the Fund’s investments will be subject to various risks which could cause fluctuations in occupancy, rental rates, operating income and expenses or which could render the sale or financing of its properties difficult or unattractive. For example, following the termination or expiration of a tenant’s lease, there may be a period of time before receiving rental payments under a replacement lease. During that period, the Fund would continue to bear fixed expenses such as interest, real estate taxes, maintenance and other operating expenses. In addition, declining economic conditions may impair the ability to attract replacement tenants and achieve rental rates equal to or greater than the rents paid under previous leases. Increased competition for tenants may require capital improvements to properties which would not have otherwise been planned.

Ultimately, to the extent it is not possible to renew leases or re-let space as leases expire, decreased cash flow from tenants will result, which could adversely impact the Fund’s operating results.

Real estate values have been historically cyclical. As the general economy grows, demand for real estate increases and occupancies and rents may increase. As occupancies and rents increase, property values increase, and new development occurs. As development may occur, occupancies, rents and property values may decline. Because leases are usually entered into for long periods and development activities often require extended times to complete, the real estate value cycle often lags the general business cycle. Because of this cycle, real estate companies may incur large swings in their profits and the prices of their securities.

The total returns available from investments in real estate generally depend on the amount of income and capital appreciation generated by the related properties. The performance of real estate, and thereby the Fund, will be reduced by any related expenses, such as expenses paid directly at the property level and other expenses that are capitalized or otherwise embedded into the cost basis of the real estate.

Valuation Risk

Certain securities in which the Fund invests may be less liquid and more difficult to value than other types of securities. When market quotations or pricing service prices are not readily available or are deemed to be unreliable, the Fund values its investments at fair value as determined in good faith pursuant to policies and procedures approved by the Board. Fair value pricing may require subjective determinations about the value of a security or other asset. As a result, there can be no assurance that fair value pricing will result in adjustments to the prices of securities or other assets or that fair value pricing will reflect actual market value, and it is possible that the fair value determined for a security or other asset will be materially different from quoted or published prices, from the prices used by others for the same security or other asset and/or from the value that actually could be or is realized upon the sale of that security or other asset.

Leverage Risk

The Fund’s use of leverage creates the opportunity for increased Common Share net income, but also creates special risks for Common Shareholders. To the extent used, there is no assurance that the Fund’s leveraging strategies will be successful. Leverage is a speculative technique that may expose the Fund to greater risk and increased costs. The Fund’s assets attributable to leverage, if any, will be invested in accordance with the Fund’s investment objectives and policies. Interest expense payable by the Fund with respect to derivatives and other forms of leverage, and dividends payable with respect to preferred shares outstanding, if any, will generally be based on shorter-term interest rates that would be periodically reset. So long as the Fund’s portfolio investments provide a higher rate of return (net of applicable Fund expenses) than the interest expenses and other costs to the Fund of such leverage, the investment of the proceeds thereof will generate more income than will be needed to pay the costs of the leverage. If so, and all other things being equal, the excess may be used to pay higher dividends to Common Shareholders than if the Fund were not so leveraged. If, however, shorter-term interest rates rise relative to the rate of return on the Fund’s portfolio, the interest and other costs to the

17 Base Prospectus | Closed-End Funds

Base Prospectus

Fund of leverage could exceed the rate of return on the debt obligations and other investments held by the Fund, thereby reducing return to Common Shareholders. In addition, fees and expenses of any form of leverage used by the Fund will be borne entirely by the Common Shareholders (and not by preferred shareholders, if any) and will reduce the investment return of the Common Shares. Therefore, there can be no assurance that the Fund’s use of leverage will result in a higher yield on the Common Shares, and it may result in losses. In addition, any preferred shares issued by the Fund are expected to pay cumulative dividends, which may tend to increase leverage risk. Leverage creates several major types of risks for Common Shareholders, including:

◾

the likelihood of greater volatility of NAV and market price of Common Shares, and of the investment return to Common Shareholders, than a comparable portfolio without leverage;

◾

the possibility either that Common Share dividends will fall if the interest and other costs of leverage rise, or that dividends paid on Common Shares will fluctuate because such costs vary over time; and

◾

the effects of leverage in a declining market or a rising interest rate environment, as leverage is likely to cause a greater decline in the NAV of the Common Shares than if the Fund were not leveraged and may result in a greater decline in the market value of the Common Shares.

In addition, the counterparties to the Fund’s leveraging transactions and any preferred shareholders of the Fund will have priority of payment over the Fund’s Common Shareholders.

Reverse repurchase agreements involve the risks that the interest income earned on the investment of the proceeds will be less than the interest expense and Fund expenses associated with the repurchase agreement, that the market value of the securities sold by the Fund may decline below the price at which the Fund is obligated to repurchase such securities and that the securities may not be returned to the Fund. There is no assurance that reverse repurchase agreements can be successfully employed. Dollar roll/buy back transactions involve the risk that the market value of the securities the Fund is required to purchase may decline below the agreed upon purchase price of those securities. Successful use of dollar rolls/buy backs may depend upon the Investment Manager’s ability to correctly predict interest rates and prepayments. There is no assurance that dollar rolls/buy backs can be successfully employed. In connection with reverse repurchase agreements and dollar rolls/buy backs, the Fund will also be subject to counterparty risk with respect to the purchaser of the securities. If the broker/dealer to whom the Fund sells securities becomes insolvent, the Fund’s right to purchase or repurchase securities may be restricted.

The Fund may engage in total return swaps, reverse repurchases, loans of portfolio securities, short sales and when-issued, delayed delivery and forward commitment transactions, credit default swaps, basis swaps and other swap agreements, purchases or sales of futures and forward contracts (including foreign currency exchange contracts), call and put options or other derivatives. The Fund’s use of such transactions gives rise to associated leverage risks described above, and may adversely affect the Fund’s income, distributions and total returns to Common

Shareholders. To the extent that any offsetting positions do not behave in relation to one another as expected, the Fund may perform as if it is leveraged through use of these derivative strategies.

Any total return swaps, reverse repurchases, loans of portfolio securities, short sales and when-issued, delayed delivery and forward commitment transactions, credit default swaps, basis swaps and other swap agreements, purchases or sales of futures and forward contracts (including foreign currency exchange contracts), call and put options or other derivatives by the Fund or counterparties to the Fund’s other leveraging transactions, if any, would have seniority over the Fund’s Common Shares.

See “The New SEC Derivatives Rule and Potential Implications for the Fund” in the Statement of Additional Information for a discussion of upcoming regulatory changes that will affect the Fund's use of derivatives and certain related instruments.

Because the fees received by the Investment Manager may increase depending on the types of leverage utilized by the Fund, the Investment Manager has a financial incentive for the Fund to use certain forms of leverage, which may create a conflict of interest between the Investment Manager, on the one hand, and the Common Shareholders, on the other hand.

Segregation and Coverage Risk

Certain portfolio management techniques, such as, among other things, entering into reverse repurchase agreement transactions, swap agreements, futures contracts or other derivative transactions, purchasing securities on a when-issued or delayed delivery basis or engaging in short sales currently may be considered senior securities unless steps are taken to segregate the Fund’s assets or otherwise cover its obligations. To avoid having these instruments considered senior securities, the Fund may segregate liquid assets with a value equal (on a daily mark-to-market basis) to its obligations under these types of leveraged transactions, enter into offsetting transactions or otherwise cover such transactions. At times, all or a substantial portion of the Fund’s liquid assets may be segregated for purposes of various portfolio transactions. The Fund may be unable to use such segregated assets for certain other purposes, which could result in the Fund earning a lower return on its portfolio than it might otherwise earn if it did not have to segregate those assets in respect of, or otherwise cover, such portfolio positions. To the extent the Fund’s assets are segregated or committed as cover, it could limit the Fund’s investment flexibility. Segregating assets and covering positions will not limit or offset losses on related positions. See “The New SEC Derivatives Rule and Potential Implications for the Fund” in the Statement of Additional Information for a discussion of upcoming regulatory changes that will affect how the asset coverage tests described above are calculated.

Short Exposure Risk

The Fund’s short sales, if any, are subject to special risks. A short sale involves the sale by the Fund of a security that it does not own with the hope of purchasing the same security at a later date at a lower price. The Fund may also enter into a short position through a forward

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PIMCO Dynamic Income Fund

commitment or a short derivative position through a futures contract or swap agreement. If the price of the security or derivative has increased during this time, then the Fund will incur a loss equal to the increase in price from the time that the short sale was entered into plus any transaction costs (i.e., premiums and interest) paid to the broker-dealer to borrow securities. Therefore, short sales involve the risk that losses may be exaggerated, potentially losing more money than the actual cost of the investment. By contrast, a loss on a long position arises from decreases in the value of the security and is limited by the fact that a security’s value cannot decrease below zero. By investing the proceeds received from selling securities short, the Fund could be deemed to be employing a form of leverage, which creates special risks. The use of leverage may increase the Fund’s exposure to long security positions and make any change in the Fund’s NAV greater than it would be without the use of leverage. This could result in increased volatility of returns. There is no guarantee that any leveraging strategy the Fund employs will be successful during any period in which it is employed.

In times of unusual or adverse market, economic, regulatory or political conditions, the Fund may not be able, fully or partially, to implement its short selling strategy. Periods of unusual or adverse market, economic, regulatory or political conditions generally may exist for long periods of time. Also, there is the risk that the third party to the short sale will not fulfill its contractual obligations, causing a loss to the Fund.

Smaller Company Risk

The general risks associated with debt instruments or equity securities are particularly pronounced for securities issued by companies with small market capitalizations. Small capitalization companies involve certain special risks. They are more likely than larger companies to have limited product lines, markets or financial resources, or to depend on a small, inexperienced management group. Securities of smaller companies may trade less frequently and in lesser volume than more widely held securities and their values may fluctuate more sharply than other securities. They may also have limited liquidity. These securities may therefore be more vulnerable to adverse developments than securities of larger companies, and the Fund may have difficulty purchasing or selling securities positions in smaller companies at prevailing market prices. Also, there may be less publicly available information about smaller companies or less market interest in their securities as compared to larger companies. Companies with medium-sized market capitalizations may have risks similar to those of smaller companies.

Derivatives Risk

The use of derivative instruments involves risks different from, and possibly greater than, the risks associated with investing directly in securities and other traditional investments. Derivatives are subject to a number of risks, such as liquidity risk, interest rate risk, market risk, credit risk, leveraging risk, counterparty risk, tax risk, and management risk, as well as risks arising from changes in applicable requirements. See also “Principal Risks of the Fund—Segregation and Coverage

Risk.” They also involve the risk of mispricing, the risk of unfavorable or ambiguous documentation and the risk that changes in the value of a derivative may not correlate perfectly with the underlying asset, rate or index.

The Fund’s use of derivatives may increase or accelerate the amount of taxes payable by Common Shareholders.

The regulation of the derivatives markets has increased over the past several years, and additional future regulation of the derivatives markets may make derivatives more costly, may limit the availability or reduce the liquidity of derivatives or may otherwise adversely affect the value or performance of derivatives.

Credit Default Swaps Risk

Credit default swap agreements may involve greater risks than if the Fund had invested in the reference obligation directly since, in addition to general market risks, credit default swaps are subject to illiquidity risk, counterparty risk and credit risk. A buyer generally also will lose its investment and recover nothing should no credit event occur and the swap is held to its termination date. If a credit event were to occur, the value of any deliverable obligation received by the seller (if any), coupled with the upfront or periodic payments previously received, may be less than the full notional value it pays to the buyer, resulting in a loss of value to the seller. When the Fund acts as a seller of a credit default swap, it is exposed to many of the same risks of leverage described herein since if an event of default occurs, the seller must pay the buyer the full notional value of the reference obligation.

Although the Fund may seek to realize gains by selling credit default swaps that increase in value, to realize gains on selling credit default swaps, an active secondary market for such instruments must exist or the Fund must otherwise be able to close out these transactions at advantageous times. In addition to the risk of losses described above, if no such secondary market exists or the Fund is otherwise unable to close out these transactions at advantageous times, selling credit default swaps may not be profitable for the Fund.

The market for credit default swaps has become more volatile as the creditworthiness of certain counterparties has been questioned and/or downgraded. The Fund will be subject to credit risk with respect to the counterparties to the credit default swap contract (whether a clearing corporation or another third party). If a counterparty’s credit becomes significantly impaired, multiple requests for collateral posting in a short period of time could increase the risk that the Fund may not receive adequate collateral. The Fund may exit its obligations under a credit default swap only by terminating the contract and paying applicable breakage fees, or by entering into an offsetting credit default swap position, which may cause the Fund to incur more losses.

Counterparty Risk

The Fund will be subject to credit risk with respect to the counterparties to the derivative contracts and other instruments entered into by the Fund or held by special purpose or structured vehicles in which the Fund invests. In the event that the Fund enters into a derivative transaction with a counterparty that subsequently becomes insolvent or becomes

19 Base Prospectus | Closed-End Funds

Base Prospectus

the subject of a bankruptcy case, the derivative transaction may be terminated in accordance with its terms and the Fund’s ability to realize its rights under the derivative instrument and its ability to distribute the proceeds could be adversely affected. If a counterparty becomes bankrupt or otherwise fails to perform its obligations under a derivative contract due to financial difficulties, the Fund may experience significant delays in obtaining any recovery (including recovery of any collateral it has provided to the counterparty) in a dissolution, assignment for the benefit of creditors, liquidation, winding-up, bankruptcy or other analogous proceeding. In addition, in the event of the insolvency of a counterparty to a derivative transaction, the derivative transaction would typically be terminated at its fair market value. If the Fund is owed this fair market value in the termination of the derivative transaction and its claim is unsecured, the Fund will be treated as a general creditor of such counterparty and will not have any claim with respect to any underlying security or asset. The Fund may obtain only a limited recovery or may obtain no recovery in such circumstances. While the Fund may seek to manage its counterparty risk by transacting with a number of counterparties, concerns about the solvency of, or a default by, one large market participant could lead to significant impairment of liquidity and other adverse consequences for other counterparties.

Equity Securities and Related Market Risk

The market price of common stocks and other equity securities may go up or down, sometimes rapidly or unpredictably. Equity securities may decline in value due to factors affecting equity securities markets generally, particular industries represented in those markets, or the issuer itself. The values of equity securities may decline due to real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates, adverse changes to credit markets or adverse investor sentiment generally. They may also decline due to labor shortages or increased production costs and competitive conditions within an industry. Equity securities generally have greater price volatility than bonds and other debt securities.

Preferred Securities Risk

In addition to equity securities risk, credit risk and possibly high yield risk, investment in preferred securities involves certain other risks. Certain preferred securities contain provisions that allow an issuer under certain conditions to skip or defer distributions. If the Fund owns a preferred security that is deferring its distribution, the Fund may be required to include the amount of the deferred distribution in its taxable income for tax purposes although it does not currently receive such amount in cash. In order to receive the special treatment accorded to regulated investment companies and their shareholders under the Internal Revenue Code of 1986, as amended (the “Code”) and to avoid U.S. federal income and/or excise taxes at the Fund level, the Fund may be required to distribute this income to shareholders in the tax year in which the income is recognized (without a corresponding receipt of cash by the Fund). Therefore, the Fund may be required to pay out as an income distribution in any such tax year an amount greater than the total amount of cash income the Fund actually received and to sell

portfolio securities, including at potentially disadvantageous times or prices, to obtain cash needed for these income distributions. Preferred securities often are subject to legal provisions that allow for redemption in the event of certain tax or legal changes or at the issuer’s call. In the event of redemption, the Fund may not be able to reinvest the proceeds at comparable rates of return. Preferred securities are subordinated to bonds and other debt securities in an issuer’s capital structure in terms of priority for corporate income and liquidation payments, and therefore will be subject to greater credit risk than those debt securities. Preferred securities may trade less frequently and in a more limited volume and may be subject to more abrupt or erratic price movements than many other securities.

Private Placements and Restricted Securities Risk

A private placement involves the sale of securities that have not been registered under the Securities Act or relevant provisions of applicable non-U.S. law to certain institutional and qualified individual purchasers, such as the Fund. In addition to the general risks to which all securities are subject, securities received in a private placement generally are subject to strict restrictions on resale, and there may be no liquid secondary market or ready purchaser for such securities. Therefore, the Fund may be unable to dispose of such securities when it desires to do so, or at the most favorable time or price. Private placements may also raise valuation risks. Restricted securities are often purchased at a discount from the market price of unrestricted securities of the same issuer reflecting the fact that such securities may not be readily marketable without some time delay. Such securities are often more difficult to value and the sale of such securities often requires more time and results in higher brokerage charges or dealer discounts and other selling expenses than does the sale of securities trading on national securities exchanges or in the over-the-counter markets. Until the Fund can sell such securities into the public markets, its holdings may be less liquid and any sales will need to be made pursuant to an exemption under the Securities Act.

Confidential Information Access Risk

In managing the Fund (and other PIMCO clients), PIMCO may from time to time have the opportunity to receive material, non-public information (“Confidential Information”) about the issuers of certain investments, including, without limitation, senior floating rate loans, other loans and related investments being considered for acquisition by the Fund or held in the Fund’s portfolio. For example, an issuer of privately placed loans considered by the Fund may offer to provide PIMCO with financial information and related documentation regarding the issuer that is not publicly available. Pursuant to applicable policies and procedures, PIMCO may (but is not required to) seek to avoid receipt of Confidential Information from the issuer so as to avoid possible restrictions on its ability to purchase and sell investments on behalf of the Fund and other clients to which such Confidential Information relates. In such circumstances, the Fund (and other PIMCO clients) may be disadvantaged in comparison to other investors, including with respect to the price the Fund pays or receives when it buys or sells an investment. Further, PIMCO’s and the Fund’s abilities to assess the

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PIMCO Dynamic Income Fund

desirability of proposed consents, waivers or amendments with respect to certain investments may be compromised if they are not privy to available Confidential Information. PIMCO may also determine to receive such Confidential Information in certain circumstances under its applicable policies and procedures. If PIMCO intentionally or unintentionally comes into possession of Confidential Information, it may be unable, potentially for a substantial period of time, to purchase or sell investments to which such Confidential Information relates.

Inflation/Deflation Risk

Inflation risk is the risk that the value of assets or income from the Fund’s investments will be worth less in the future as inflation decreases the value of payments at future dates. As inflation increases, the real value of the Fund’s portfolio could decline. Inflation has recently increased and it cannot be predicted whether it may decline. Deflation risk is the risk that prices throughout the economy decline over time. Deflation may have an adverse effect on the creditworthiness of issuers and may make issuer default more likely, which may result in a decline in the value of the Fund’s portfolio and Common Shares.

Regulatory Changes Risk

Financial entities, such as investment companies and investment advisers, are generally subject to extensive government regulation and intervention. Government regulation and/or intervention may change the way the Fund is regulated, affect the expenses incurred directly by the Fund and the value of its investments, and limit and /or preclude the Fund’s ability to achieve its investment objectives. Government regulation may change frequently and may have significant adverse consequences. The Fund and the Investment Manager have historically been eligible for exemptions from certain regulations. However, there is no assurance that the Fund and the Investment Manager will continue to be eligible for such exemptions. Actions by government entities may also impact certain instruments in which the Fund invests.

Moreover, government regulation may have unpredictable and unintended effects. Legislative or regulatory actions to address perceived liquidity or other issues in fixed income markets generally, or in particular markets such as the municipal securities market, may alter or impair the Fund’s ability to pursue its investment objectives or utilize certain investment strategies and techniques.

Current rules related to credit risk retention requirements for ABS may increase the cost to originators, securitizers and, in certain cases, asset managers of SPEs in which the Fund may invest. The impact of the risk retention rules on the securitization markets is uncertain. These requirements may increase the costs to originators, securitizers, and, in certain cases, collateral managers of securitization vehicles in which the Fund may invest, which costs could be passed along to the Fund as an investor in such vehicles. In addition, the costs imposed by the risk retention rules on originators, securitizers and/or collateral managers may result in a reduction of the number of new offerings of ABS and thus in fewer investment opportunities for the Fund. A reduction in the

number of new securitizations could also reduce liquidity in the markets for certain types of financial assets, which in turn could negatively affect the returns on the Fund’s investment.

Regulatory Risk - London Interbank Offered Rate (“LIBOR”)

The Fund’s investments (including, but not limited to, repurchase agreements, collateralized loan obligations and mortgage-backed securities), payment obligations and financing terms may rely in some fashion on the London Interbank Offered Rate (“LIBOR”). LIBOR is an average interest rate, determined by the ICE Benchmark Administration that banks charge one another for the use of short-term money. On July 27, 2017, the Chief Executive of the FCA announced that after 2021 it would cease its active encouragement of banks to provide the quotations needed to sustain LIBOR due to the absence of an active market for interbank unsecured lending and other reasons. On March 5, 2021, the FCA publicly announced that all U.S. Dollar LIBOR settings will either cease to be provided by any administrator or will no longer be representative (i) immediately after December 31, 2021 for one-week and two-month U.S. Dollar LIBOR settings and (ii) immediately after June 30, 2023 for the remaining U.S. Dollar LIBOR settings. As of January 1, 2022, as a result of supervisory guidance from U.S. regulators, some U.S. regulated entities have ceased entering into new LIBOR contracts with limited exceptions. While publication of the one-, three- and six-month Sterling and Japanese yen LIBOR settings will continue at least through calendar year 2022 on the basis of a changed methodology (known as “synthetic LIBOR”), these rates have been designated by the FCA as unrepresentative of the underlying market they seek to measure and are solely available for use in legacy transactions. Certain bank-sponsored committees in other jurisdictions, including Europe, the United Kingdom, Japan and Switzerland, have selected alternative reference rates denominated in other currencies. Although the transition process away from LIBOR has become increasingly well-defined in advance of the anticipated discontinuation date, there remains uncertainty regarding the future utilization of LIBOR and the nature of any replacement rate (e.g., the Secured Overnight Financing Rate, which is intended to replace U.S. dollar LIBOR and measures the cost of overnight borrowings through repurchase agreement transactions collateralized with U.S. Treasury securities). Any potential effects of the transition away from LIBOR on the Fund or on certain instruments in which the Fund invests can be difficult to ascertain, and they may vary depending on factors that include, but are not limited to: (i) existing fallback or termination provisions in individual contracts and (ii) whether, how, and when industry participants develop and adopt new reference rates and fallbacks for both legacy and new products and instruments. For example, certain of the Fund’s investments may involve individual contracts that have no existing fallback provision or language that contemplates the discontinuation of LIBOR, and those investments could experience increased volatility or illiquidity as a result of the transition process. In addition, interest rate provisions included in such contracts, or in contracts or other arrangements entered into by the Fund, may need to be renegotiated.

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Base Prospectus

On March 15, 2022, the Adjustable Interest Rate (LIBOR) Act was signed into law. This law provides a statutory fallback mechanism on a nationwide basis to replace LIBOR with a benchmark rate that is selected by the Board of Governors of the Federal Reserve System and based on the Secured Overnight Financing Rate for certain contracts that reference LIBOR and contain no, or insufficient, fallback provisions. It is expected that implementing regulations in respect of the law will follow. The transition of investments from LIBOR to a replacement rate as a result of amendment, application of existing fallbacks, statutory requirements or otherwise may also result in a reduction in the value of certain instruments held by the Fund, a change in the cost of borrowing or the dividend rate for any preferred shares that may be issued by the Fund, or a reduction in the effectiveness of related Fund transactions such as hedges. Any such effects of the transition away from LIBOR, as well as other unforeseen effects, could result in losses to the Fund.

Regulatory Risk – Commodity Pool Operator

The CFTC has adopted regulations that subject registered investment companies and their investment advisers to regulation by the CFTC if the registered investment company invests more than a prescribed level of its liquidation value in futures, options on futures or commodities, swaps, or other financial instruments regulated under the Commodity Exchange Act (“CEA”) and the rules thereunder (“commodity interests”), or if the Fund markets itself as providing investment exposure to such instruments. The Investment Manager is registered with the CFTC as a CPO. However, with respect to the Fund, the Investment Manager has claimed an exclusion from registration as a CPO pursuant to CFTC Rule 4.5. For the Investment Manager to remain eligible for this exclusion, the Fund must comply with certain limitations, including limits on its ability to use any commodity interests and limits on the manner in which the Fund holds out its use of such commodity interests. These limitations may restrict the Fund’s ability to pursue its investment objectives and strategies, increase the costs of implementing its strategies, result in higher expenses for the Fund, and/or adversely affect the Fund’s total return. To the extent the Fund becomes ineligible for this exclusion from CFTC regulation, the Fund may consider steps in order to continue to qualify for exemption from CFTC regulation, or may determine to operate subject to CFTC regulation.

REIT Risk

REITs are pooled investment vehicles that own, and usually operate, income-producing real estate. Some REITs also finance real estate. If a REIT meets certain requirements, including distributing to shareholders substantially all of its taxable income (other than net capital gains), then it is not typically taxed on the income distributed to shareholders. Therefore, REITs may pay higher dividends than other issuers.

REITs can be divided into three basic types: Equity REITs, Mortgage REITs and Hybrid REITs. Equity REITs invest the majority of their assets directly in real property. They derive their income primarily from rents received and any profits on the sale of their properties. Mortgage REITs invest the majority of their assets in real estate mortgages and derive

most of their income from mortgage interest payments. As its name suggests, Hybrid REITs combine characteristics of both Equity REITs and Mortgage REITs.

An investment in a REIT, or in a real estate linked derivative instrument linked to the value of a REIT, is subject to the risks that impact the value of the underlying properties of the REIT. These risks include loss to casualty or condemnation, and changes in supply and demand, interest rates, zoning laws, regulatory limitations on rents, property taxes and operating expenses. Other factors that may adversely affect REITs include poor performance by management of the REIT, changes to the tax laws, or failure by the REIT to qualify for favorable tax treatment. REITs are also subject to default by borrowers and self-liquidation, and are heavily dependent on cash flow. Some REITs lack diversification because they invest in a limited number of properties, a narrow geographic area, or a single type of property. Mortgage REITs may be impacted by the quality of the credit extended.

Liquidity Risk

Liquidity risk exists when particular investments are difficult to purchase or sell. Illiquid investments are investments that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment. Illiquid investments may become harder to value, especially in changing markets. The Fund’s investments in illiquid investments may reduce the returns of the Fund because it may be unable to sell the illiquid investments at an advantageous time or price or possibly require the Fund to dispose of other investments at unfavorable times or prices in order to satisfy its obligations, which could prevent the Fund from taking advantage of other investment opportunities. Additionally, the market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. To the extent that the Fund invests in securities of companies with smaller market capitalizations, foreign (non-U.S.) securities, Rule 144A securities, illiquid sectors of fixed income securities, derivatives or securities with substantial market and/or credit risk, the Fund will tend to have greater exposure to liquidity risk.

Further fixed income securities with longer durations until maturity face heightened levels of liquidity risk as compared to fixed income securities with shorter durations until maturity. The risks associated with illiquid instruments may be particularly acute in situations in which the Fund’s operations require cash (such as in connection with repurchase offers) and could result in the Fund borrowing to meet its short-term needs or incurring losses on the sale of illiquid instruments. It may also be the case that other market participants may be attempting to liquidate fixed income holdings at the same time as the Fund, causing increased supply in the market and contributing to liquidity risk and downward pricing pressure.

To the extent the Fund invests in Alt Lending ABS, the Alt Lending ABS in which the Fund invests are typically not listed on any securities exchange and not registered under the Securities Act. In addition, the

June 23, 2022 | Base Prospectus 22

PIMCO Dynamic Income Fund

Fund anticipates that these instruments may only be sold to a limited number of investors and may have a limited or non-existent secondary market. Accordingly, the Fund currently expects that certain of its investments in Alt Lending ABS will face heightened levels of liquidity risk. Although currently, there is generally no active reliable, secondary market for certain Alt Lending ABS, a secondary market for these alternative lending-related instruments may develop.

Tax Risk

The Fund has elected to be treated as a “regulated investment company” (a “RIC”) under the Code and intends each year to qualify and be eligible to be treated as such, so that it generally will not be subject to U.S. federal income tax on its net investment income or net short-term or long-term capital gains distributed to shareholders. In order to qualify and be eligible for such treatment, the Fund must meet certain asset diversification tests, derive at least 90% of its gross income for such year from certain types of qualifying income, and distribute to its shareholders at least 90% of its “investment company taxable income” as that term is defined in the Code (which includes, among other things, dividends, taxable interest and the excess of any net short-term capital gains over net long-term capital losses, as reduced by certain deductible expenses).

The Fund’s investment strategy will potentially be limited by its intention to continue qualifying for treatment as a RIC, and can limit the Fund’s ability to continue qualifying as such. The tax treatment of certain of the Fund’s investments under one or more of the qualification or distribution tests applicable to RICs is uncertain. An adverse determination or future guidance by the Internal Revenue Services (“IRS”) or a change in law might affect the Fund’s ability to qualify or be eligible for treatment as a RIC. Income and gains from certain of the Fund’s activities, including fees received in connection with the origination of loans, may not constitute qualifying income to a RIC for purposes of the 90% gross income test. If the Fund were to treat income or gain from a particular investment or activity as qualifying income and the income or gain were later determined not to constitute qualifying income and, together with any other nonqualifying income, caused the Fund’s nonqualifying income to exceed 10% of its gross income in any taxable year, the Fund would fail to qualify as a RIC unless it is eligible to and does pay a tax at the Fund level.

If, in any year, the Fund were to fail to qualify for treatment as a RIC under the Code, and were ineligible to or did not otherwise cure such failure, the Fund would be subject to tax on its taxable income at corporate rates and, when such income is distributed, shareholders would be subject to further tax on such distributions to the extent of the Fund’s current or accumulated earnings and profits.

Subsidiary Risk

To the extent the Fund invests through one or more of its Subsidiaries, the Fund would be exposed to the risks associated with such Subsidiary’s investments. Such Subsidiaries would likely not be registered as investment companies under the 1940 Act and therefore would not be subject to all of the investor protections of the 1940 Act.

Changes in the laws of the United States and/or the jurisdiction in which a Subsidiary is organized could result in the inability of the Fund and/or the Subsidiary to operate as intended and could adversely affect the Fund.

Portfolio Turnover Risk

The Investment Manager manages the Fund without regard generally to restrictions on portfolio turnover. The use of futures contracts and other derivative instruments with relatively short maturities may tend to exaggerate the portfolio turnover rate for the Fund. Trading in fixed income securities does not generally involve the payment of brokerage commissions, but does involve indirect transaction costs. The use of futures contracts and other derivative instruments may involve the payment of commissions to futures commission merchants or other intermediaries. Higher portfolio turnover involves correspondingly greater expenses to the Fund, including brokerage commissions or dealer mark-ups and other transaction costs on the sale of securities and reinvestments in other securities. The higher the rate of portfolio turnover of the Fund, the higher these transaction costs borne by the Fund generally will be. Such sales may result in realization of taxable capital gains (including short-term capital gains, which are generally taxed to shareholders at ordinary income tax rates when distributed net of short-term capital losses and net long-term capital losses), and may adversely impact the Fund’s after-tax returns.

Operational Risk

An investment in the Fund, like any fund, involves operational risks arising from factors such as processing errors, human errors, inadequate or failed internal or external processes, failures in systems and technology, changes in personnel and errors caused by third-party service providers. The occurrence of any of these failures, errors or breaches could result in a loss of information, regulatory scrutiny, reputational damage or other events, any of which could have a material adverse effect on the Fund. While the Fund seeks to minimize such events through controls and oversight, there may still be failures that could cause losses to the Fund.

Other Investment Companies Risk

When investing in an investment company, the Fund generally will bear its ratable share of that investment company’s expenses and remain subject to payment of the Fund’s management fees and other expenses with respect to assets so invested. Common Shareholders could therefore be subject to duplicative expenses to the extent the Fund invests in other investment companies. In addition, the securities of other investment companies may also be leveraged and will therefore be subject to the same leverage risks.

Cybersecurity Risk

As the use of technology has become more prevalent in the course of business, the Fund is potentially more susceptible to operational and information security risks resulting from breaches in cyber security. A breach in cyber security refers to both intentional and unintentional cyber events from outside threat actors or internal resources that may,

23 Base Prospectus | Closed-End Funds

Base Prospectus

among other things, cause the Fund to lose proprietary information, suffer data corruption and/or destruction, lose operational capacity, result in the unauthorized release or other misuse of confidential information, or otherwise disrupt normal business operations. Cyber security breaches may involve unauthorized access to the Fund’s digital information systems (e.g., through “hacking” or malicious software coding), and may come from multiple sources, including outside attacks such as denial-of-service attacks (i.e., efforts to make network services unavailable to intended users) or cyber extortion, including exfiltration of data held for ransom and/or “ransomware” attacks that renders systems inoperable until ransom is paid, or insider actions. In addition, cyber security breaches involving the Fund’s third party service providers (including but not limited to advisers, sub-advisers, administrators, transfer agents, custodians, vendors, suppliers, distributors and other third parties), trading counterparties or issuers in which the Fund invests can also subject the Fund to many of the same risks associated with direct cyber security breaches or extortion of company data. Moreover, cyber security breaches involving trading counterparties or issuers in which the Fund invests could adversely impact such counterparties or issuers and cause the Fund’s investment to lose value.

Cyber security failures or breaches may result in financial losses to the Fund and its shareholders. These failures or breaches may also result in disruptions to business operations, potentially resulting in financial losses; interference with the Fund’s ability to calculate its NAV, process shareholder transactions or otherwise transact business with shareholders; impediments to trading; violations of applicable privacy and other laws; regulatory fines; penalties; third party claims in litigation; reputational damage; reimbursement or other compensation costs; additional compliance and cyber security risk management costs and other adverse consequences. In addition, substantial costs may be incurred in order to prevent any cyber incidents in the future.

Like with operational risk in general, the Fund has established business continuity plans and risk management systems designed to reduce the risks associated with cyber security. However, there are inherent limitations in these plans and systems, including that certain risks may not have been identified, in large part because different or unknown threats may emerge in the future. As such, there is no guarantee that such efforts will succeed, especially because the Fund does not directly control the cyber security systems of issuers in which the Fund may invest, trading counterparties or third party service providers to the Fund. Such entities have experienced cyber attacks and other attempts to gain unauthorized access to systems from time to time, and there is no guarantee that efforts to prevent or mitigate the effects of such attacks or other attempts to gain unauthorized access will be successful. There is also a risk that cyber security breaches may not be detected. The Fund and its shareholders may suffer losses as a result of a cyber security breach related to the Fund, its service providers, trading counterparties or the issuers in which the Fund invests.

Potential Conflicts of Interest Risk—Allocation of Investment Opportunities

The Investment Manager and its affiliates are involved worldwide with a broad spectrum of financial services and asset management activities and may engage in the ordinary course of business in activities in which their interests or the interests of their clients may conflict with those of the Fund. The Investment Manager may provide investment management services to other funds and discretionary managed accounts that follow an investment program similar to that of the Fund. Subject to the requirements of the 1940 Act, the Investment Manager intends to engage in such activities and may receive compensation from third parties for its services. The results of the Fund’s investment activities may differ from those of other accounts managed by the Investment Manager or its affiliates, and it is possible that the Fund could sustain losses during periods in which one or more other accounts managed by the Investment Manager or its affiliates, including proprietary accounts, achieve profits on their trading.

Repurchase Agreements Risk

The Fund may enter into repurchase agreements, in which the Fund purchases a security from a bank or broker-dealer, which agrees to repurchase the security at the Fund’s cost plus interest within a specified time. If the party agreeing to repurchase should default, the Fund will seek to sell the securities which it holds. This could involve procedural costs or delays in addition to a loss on the securities if their value should fall below their repurchase price. Repurchase agreements may be or become illiquid. These events could also trigger adverse tax consequences for the Fund.

Special Purpose Acquisition Companies (“SPACs”) Risk

The Fund may invest in securities of SPACs or similar special purpose entities that pool funds to seek potential acquisition opportunities. Unless and until an acquisition is completed, a SPAC generally invests its assets (less a portion retained to cover expenses) in US government securities, money market securities or holds cash; if an acquisition that meets the requirements for the SPAC is not completed within a pre-established period of time, the invested funds are returned to the entity’s shareholders. Because SPACs and similar entities are in essence blank check companies without operating history or ongoing business other than seeking acquisitions, the value of their securities is particularly dependent on the ability of the entity’s management to identify and complete a profitable acquisition. A SPAC’s structure may result in significant dilution of a stockholder’s share value immediately upon the completion of a business combination due to, among other reasons, interests held by the SPAC sponsor, conversion of warrants into additional shares, shares issued in connection with a business combination and/or certain embedded costs. There is no guarantee that the SPACs in which the Fund invests will complete an acquisition or that any acquisitions that are completed will be profitable. Some SPACs may pursue acquisitions only within certain industries or regions, which may increase the volatility of their prices. In addition, these securities, which are typically traded in the over-the-counter market, may be considered illiquid and/or be subject to restrictions on resale.

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PIMCO Dynamic Income Fund

Structured Investments Risk

Holders of structured products, including structured notes, credit-linked notes and other types of structured products, bear the risks of the underlying investments, index or reference obligation and are subject to counterparty risk. The Fund may have the right to receive payments only from the structured product, and generally does not have direct rights against the issuer or the entity that sold the assets to be securitized. Although it is difficult to predict whether the prices of indices and securities underlying structured products will rise or fall, these prices (and, therefore, the prices of structured products) are generally influenced by the same types of political and economic events that affect issuers of securities and capital markets generally. Structured products generally entail risks associated with derivative instruments.

Collateralized Bond Obligations, Collateralized Loan Obligations and Collateralized Debt Obligations Risk

CBOs, CLOs and CDOs may charge management fees and administrative expenses. For CBOs, CLOs and CDOs, the cash flows from the trust are split into two or more portions, called tranches, varying in risk and yield. The riskiest portion is the equity tranche which generally bears losses in connection with the first defaults, if any, on the bonds or loans in the trust. A senior tranche from a CLO, CBO and CDO trust typically has higher credit ratings and lower yields than the underlying securities. CLO tranches, even senior ones, can experience substantial losses due to actual defaults, increased sensitivity to defaults due to collateral default and disappearance of protecting tranches, market anticipation of defaults and aversion to CLO, CBO or other CDO securities. The risks of an investment in a CLO, CBO or other CDO depend largely on the type of the collateral securities and the class/tranche of the instrument in which the Fund invests. Normally, CLOs, CBOs and other CDOs are privately offered and sold, and thus are not registered under the securities laws. Investments in CLOs, CBOs and CDOs may be or become illiquid. In addition to the normal risks associated with debt instruments (e.g., interest rate risk and credit risk), CLOs, CBOs and CDOs carry additional risks including, but not limited to: (i) the possibility that distributions from the collateral will not be adequate to make interest or other payments; (ii) the risk that the quality of the collateral may decline in value or default; (iii) the risk that the Fund may invest in CBOs, CLOs or other CDOs that are subordinate to other classes; and (iv) the risk that the complex structure of the security may not be fully understood at the time of investment and may produce disputes with the issuer or others and may produce unexpected investment results.

Focused Investment Risk

To the extent that the Fund focuses its investments in a particular sector, it may be susceptible to loss due to adverse developments affecting that sector, including (but not limited to): governmental regulation; inflation; rising interest rates; cost increases in raw materials, fuel and other operating expenses; technological innovations that may render existing products and equipment obsolete; competition from new entrants; high research and development costs; increased costs associated with compliance with environmental or other governmental regulations; and

other economic, business or political developments specific to that sector. Furthermore, the Fund may invest a substantial portion of its assets in companies in related sectors that may share common characteristics, are often subject to similar business risks and regulatory burdens, and whose securities may react similarly to the types of developments described above, which will subject the Fund to greater risk. The Fund also will be subject to focused investment risk to the extent that it invests a substantial portion of its assets in a particular issuer, market, asset class, country or geographic region.

Market Disruptions Risk

The Fund is subject to investment and operational risks associated with financial, economic and other global market developments and disruptions, including those arising from war, terrorism, market manipulation, government interventions, defaults and shutdowns, political changes or diplomatic developments, public health emergencies (such as the spread of infectious diseases, pandemics and epidemics) and natural/environmental disasters, which can all negatively impact the securities markets, interest rates, secondary trading, ratings, credit risk, inflation, deflation, other factors relating to the Fund’s investments or the Investment Manager’s operations and the value of an investment in the Fund, its distributions and its returns. These events can also impair the technology and other operational systems upon which the Fund’s service providers, including PIMCO as the Fund’s investment adviser, rely, and could otherwise disrupt the Fund’s service providers’ ability to fulfill their obligations to the Fund.

For example, the spread of an infectious respiratory illness caused by a novel strain of coronavirus (known as COVID-19) has caused volatility, severe market dislocations and liquidity constraints in many markets, including markets for the securities the Fund holds, and may adversely affect the Fund's investments and operations.

Debt Securities Risk

Debt securities are generally subject to the risks described below and further herein:

Issuer risk. The value of debt securities may decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage, reduced demand for the issuer’s goods and services, historical and prospective earnings of the issuer and the value of the assets of the issuer. A change in the financial condition of a single issuer may affect securities markets as a whole. These risks can apply to the Common Shares issued by the Fund and to the issuers of securities and other instruments in which the Fund invests.

Interest rate risk. The market value of debt securities changes in response to interest rate changes and other factors. Interest rate risk is the risk that prices of debt securities will increase as interest rates fall and decrease as interest rates rise, which would be reflected in the Fund’s NAV. The Fund may lose money if short-term or long-term interest rates rise sharply in a manner not anticipated by the Fund’s management. Moreover, because rates on certain floating rate debt securities typically reset only periodically, changes in prevailing interest rates (and particularly sudden and significant changes) can be expected

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Base Prospectus

to cause some fluctuations in the NAV of the Fund to the extent that it invests in floating rate debt securities.

Prepayment risk. During periods of declining interest rates, borrowers may prepay principal. This may force the Fund to reinvest in lower yielding securities, resulting in a possible decline in the Fund’s income and distributions.

Credit risk. Credit risk is the risk that one or more debt securities in the Fund’s portfolio will decline in price or fail to pay interest or principal when due because the issuer of the security experiences a decline in its financial status. Credit risk is increased when a portfolio security is downgraded or the perceived creditworthiness of the issuer deteriorates.

Reinvestment risk. Reinvestment risk is the risk that income from the Fund’s portfolio will decline if the Fund invests the proceeds from matured, traded or called fixed income securities at market interest rates that are below the portfolio’s current earnings rate.

Duration and maturity risk. The Fund may seek to adjust the duration or maturity of its investments in debt securities based on its assessment of current and projected market conditions. The Fund may incur costs in seeking to adjust the average duration or maturity of its portfolio of debt securities. There can be no assurances that the Fund’s assessment of current and projected market conditions will be correct or that any strategy to adjust duration or maturity will be successful.

Zero-Coupon Bond, Step-Ups and Payment-in-Kind Securities Risk

The market prices of zero-coupon, step-ups and payment-in-kind securities are generally are more volatile than the prices of securities that pay interest periodically and in cash, and are likely to respond to changes in interest rates to a greater degree than other types of debt securities with similar maturities and credit quality. Because zero-coupon securities bear no interest, their prices are especially volatile. And because zero-coupon bondholders do not receive interest payments, the prices of zero-coupon securities generally fall more dramatically than those of bonds that pay interest on a current basis when interest rates rise. The market for zero-coupon and payment-in-kind securities may suffer decreased liquidity. In addition, as these securities may not pay cash interest, the Fund’s investment exposure to these securities and their risks, including credit risk, will increase during the time these securities are held in the Fund’s portfolio. Further, to maintain its qualification for treatment as a RIC and to avoid Fund-level U.S. federal income and/or excise taxes, the Fund is required to distribute to its shareholders any income it is deemed to have received in respect of such investments, and the value of paid-in-kind interest, notwithstanding that cash has not been received currently.

Consequently, the Fund may have to dispose of portfolio securities under disadvantageous circumstances to generate the cash, or may have to leverage itself by borrowing the cash to satisfy this distribution requirement. The required distributions, if any, would result in an increase in the Fund’s exposure to these securities. Zero coupon bonds, step-ups and payment-in-kind securities allow an issuer to avoid or

delay the need to generate cash to meet current interest payments and, as a result, may involve greater credit risk than bonds that pay interest currently or in cash.

Sovereign Debt Risk

In addition to the other risks applicable to debt investments, sovereign debt (debt issued by a foreign government) may decline in value as a result of default or other adverse credit event resulting from an issuer’s inability or unwillingness to make principal or interest payments in a timely fashion. A sovereign entity’s failure to make timely payments on its debt can result from many factors, including, without limitation, insufficient foreign currency reserves or an inability to sufficiently manage fluctuations in relative currency valuations, an inability or unwillingness to satisfy the demands of creditors and/or relevant supranational entities regarding debt service or economic reforms, the size of the debt burden relative to economic output and tax revenues, cash flow difficulties, and other political and social considerations. The risk of loss to the Fund in the event of a sovereign debt default or other adverse credit event is heightened by the unlikelihood of any formal recourse or means to enforce its rights as a holder of the sovereign debt. In addition, sovereign debt restructurings, which may be shaped by entities and factors beyond the Fund’s control, may result in a loss in value of the Fund’s sovereign debt holdings.

Certain Affiliations

Certain broker-dealers may be considered to be affiliated persons of the Fund and/or the Investment Manager due to their possible affiliations with Allianz SE, the ultimate parent of the Investment Manager. Absent an exemption from the SEC or other regulatory relief, the Fund is generally precluded from effecting certain principal transactions with affiliated brokers, and its ability to purchase securities being underwritten by an affiliated broker or a syndicate including an affiliated broker, or to utilize affiliated brokers for agency transactions, is subject to restrictions. This could limit the Fund’s ability to engage in securities transactions and take advantage of market opportunities.

Anti-Takeover Provisions

The Fund’s Amended and Restated Agreement and Declaration of Trust (the “Declaration”) includes provisions that could limit the ability of other entities or persons to acquire control of the Fund or to convert the Fund to open-end status. See “Anti-Takeover and Other Provisions in the Declaration of Trust.” These provisions in the Declaration could have the effect of depriving the Common Shareholders of opportunities to sell their Common Shares at a premium over the then-current market price of the Common Shares or at NAV.

Distribution Rate Risk

Although the Fund may seek to maintain level distributions, the Fund’s distribution rates may be affected by numerous factors, including but not limited to changes in realized and projected market returns, fluctuations in market interest rates, Fund performance, and other

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PIMCO Dynamic Income Fund

factors. There can be no assurance that a change in market conditions or other factors will not result in a change in the Fund’s distribution rate or that the rate will be sustainable in the future.

For instance, during periods of low or declining interest rates, the Fund’s distributable income and dividend levels may decline for many reasons. For example, the Fund may have to deploy uninvested assets (whether from purchases of Fund shares, proceeds from matured, traded or called debt obligations or other sources) in new, lower yielding instruments. Additionally, payments from certain instruments that may be held by the Fund (such as variable and floating rate securities) may be negatively impacted by declining interest rates, which may also lead to a decline in the Fund’s distributable income and dividend levels.

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PIMCO Dynamic Income Fund

Summary of Fund Expenses

The following table is intended to assist investors in understanding the fees and expenses (annualized) that an investor in Common Shares of the Fund would bear, directly or indirectly, as a result of an offering. The table reflects the use of leverage in the form of reverse repurchase agreements in an amount equal to approximately 43% of the Fund’s total managed assets (including assets attributable to reverse repurchase agreements), which reflects the percentage of the Fund's total managed assets attributable to such leverage as of December 31, 2021, and shows Fund expenses as a percentage of net assets attributable to Common Shares. The percentage above does not reflect the Fund’s use of other forms of economic leverage, such as credit default swaps or other derivative instruments. The extent of the Fund’s assets attributable to leverage following an offering, and the Fund’s associated expenses, are likely to vary (perhaps significantly) from these assumptions.

Shareholder Transaction Expenses:

Sales load (as a percentage of offering price)(1)	[--](1)
Offering Expenses Borne by Common Shareholders (as a percentage of offering price)(2)	[--]
Dividend Reinvestment Plan Fees(3)	None(2)

(1)

In the event that the Common Shares to which this prospectus relates are sold to or through underwriters or dealer managers, a corresponding prospectus supplement will disclose the applicable sales load and/or commission.

(2)

The related prospectus supplement will disclose the estimated amount of offering expenses, the offering price and the offering expenses borne by the Fund and indirectly by all of its Common Shareholders as a percentage of the offering price.

(3)

You will pay brokerage charges if you direct your broker or the plan agent to sell your Common Shares that you acquired pursuant to a dividend reinvestment plan. You may also pay a pro rata share of brokerage commissions incurred in connection with open-market purchases pursuant to the Fund's Dividend Reinvestment Plan. See “Dividend Reinvestment Plan.”

Annual Expenses

	Percentage of Net Assets Attributable to Common Shares (reflecting leverage attributable to reverse repurchase agreements)
Management Fees(1)	1.95%
Interest Payments on Borrowed Funds(2)	1.18%
Other Expenses(3)	0.02%
Total Annual Expenses(4)	3.15%

(1)

Management Fees have been restated to reflect the reduction in the Fund's contractual management fee rate and the reorganization, effective December 10, 2021, of PIMCO Dynamic Credit and Mortgage Income Fund and PIMCO Income Opportunity Fund with and into the Fund (the “Reorganization”). Management Fees include fees payable to the Investment Manager for advisory services and for supervisory, administrative and other services. The Fund pays for the advisory, supervisory and administrative services it requires under what is essentially an all-in fee structure (the “unified management fee”). Pursuant to an investment management agreement, PIMCO is paid a Management Fee of 1.10% of the Fund’s average daily total managed assets. The Fund (and not PIMCO) will be responsible for certain fees and expenses, which are reflected in the table above, that are not covered by the unified management fee under the investment management agreement. Please see “Management of the Fund –Investment Management Agreement” for an explanation of the unified management fee and definition of “total managed assets.”

(2)

Interest Payments on Borrowed Funds have been restated to reflect the Fund's use of leverage in the form of reverse repurchase agreements, which represented approximately 43% of the Fund's total managed assets including assets attributable to reverse repurchase agreements, and a weighted average interest rate of 1.38% (which is intended to reflect the Reorganization). See “Use of Leverage—Effects of Leverage.” The actual amount of interest expense borne by the Fund will vary over time in accordance with the level of the Fund’s use of reverse repurchase agreements, dollar rolls and/or borrowings and variations in market interest rates. Borrowing expense is required to be treated as an expense of the Fund for accounting purposes. Any associated income or gains (or losses) realized from leverage obtained through such instruments is not reflected in the Annual Expenses table above, but would be reflected in the Fund’s performance results.

(3)

Other expenses are estimated for the Fund’s current fiscal year ending June 30, 2022.

(4)

“Interest Payments on Borrowed Funds” is borne by the Fund separately from the management fees paid to PIMCO. Excluding such expense, Total Annual Expenses are 1.97%.

Example

The following example illustrates the expenses that you would pay on a $1,000 investment in Common Shares of the Fund, assuming (1) that the Fund’s net assets do not increase or decrease, (2) that the Fund incurs total annual expenses of 3.15% of net assets attributable to Common Shares in years 1 through 10 (assuming assets attributable to reverse repurchase agreements representing approximately 43% of Fund total managed assets) and (3) a 5% annual return(1):

	1 Year	3 Years	5 Years	10 Years
Total Expenses Incurred	$32	$97	$165	$346

(1)

The example above should not be considered a representation of future expenses. Actual expenses may be higher or lower than those shown. The example assumes that the estimated Interest Payments on Borrowed Funds and Other Expenses set forth in the Annual Expenses table are accurate, that the rate listed under Total Annual Expenses remains the same each year and that all dividends and distributions are reinvested at NAV. Actual expenses may be greater or less than those assumed. Moreover, the Fund’s actual rate of return may be greater or less than the hypothetical 5% annual return shown in the example. The example does not include commissions or estimated offering expenses, which would cause the expenses shown in the example to increase. In connection with an offering of Common Shares, the prospectus supplement will set forth an example including sales load and estimated offering costs.

Closed-End Funds | Base Prospectus 28

PIMCO Dynamic Income Fund

Financial Highlights

The information shown in the table below for the six months ended December 31, 2021 is unaudited. The information in the table below for the fiscal years ended June 30, 2021, June 30, 2020, June 30, 2019, June 30, 2018, and June 30, 2017 is derived from the Fund’s financial statements for the fiscal year ended June 30, 2021 audited by PricewaterhouseCoopers LLP (“PwC”), whose report on such financial statements is contained in the Fund’s June 30, 2021 Annual Report and is incorporated by reference into the Statement of Additional Information.

The information shown in the table below for the fiscal year ended March 31, 2014 and the fiscal period ended March 31, 2013(1) is derived from the Fund’s financial statements for the fiscal year ended March 31, 2014.

The information in the table below for the period ended June 30, 2015,(2) and the fiscal year ended March 31, 2015 is derived from the Fund’s financial statements for the fiscal year ended June 30, 2019.

The information shown in the table below for the fiscal year ended June 30, 2016 is derived from the Fund’s financial statements for the fiscal year ended June 30, 2020.

The Fund commenced operations on May 30, 2012.

On December 16, 2014, the Board approved a change of the Fund’s fiscal year end from December 31 to June 30. Information is provided for the “stub” period from April 1, 2015 through the Fund’s new fiscal year end of June 30, 2015.

		Investment Operations			Less Distributions(c)

Selected Per Share Data for the Year or Period Ended^:	Net Asset Value Beginning of Year or Period(a)	Net Investment Income(Loss)(b)	Net Realized/ Unrealized Gain (Loss)	Total	From Net Investment Income	From Net Realized Capital Gains	Tax Basis Return of Capital
PIMCO Dynamic Income Fund (Consolidated)
07/01/2021 - 12/31/2021+	$25.23	$1.41	$(0.88)	$0.53	$(1.32)	$0.00	$0.00
06/30/2021	22.59	2.51	2.57	5.08	(2.52)	0.00	(0.13)
06/30/2020	28.29	2.92	(5.80)	(2.88)	(3.07)	0.00	0.00
06/30/2019	28.98	2.73	(0.37)	2.36	(3.15)	0.00	0.00
06/30/2018	28.32	2.95	0.18	3.13	(2.65)	0.00	0.00
06/30/2017	26.56	2.60	3.18	5.78	(4.10)	0.00	0.00
06/30/2016	31.38	3.87	(3.45)	0.42	(4.25)	(0.99)	0.00
04/01/2015 – 06/30/2015(f)	30.74	0.80	0.47	1.27	(0.63)	0.00	0.00
03/31/2015	32.11	3.25	(0.49)	2.76	(4.13)	0.00	0.00
03/31/2014	30.69	3.70	1.24	4.94	(3.29)	(0.23)	0.00
05/30/2012 – 03/31/2013	23.88	2.79	6.50	9.29	(2.18)	(0.27)	0.00

Unaudited

A zero balance may reflect actual amounts rounding to less than $0.01 or 0.01%.

Annualized, except for organization expense, if any.

(a)

Includes adjustments required by U.S. GAAP and may differ from net asset values and performance reported elsewhere by the Fund.

(b)

Per share amounts based on average number of common shares outstanding during the year or period.

(c)

The tax characterization of distributions is determined in accordance with Federal income tax regulations. See Note 2, Distributions – Common Shares, in the Notes to Financial Statements for more information.

(d)

Total investment return is calculated assuming a purchase of a share at the market price on the first day and a sale of a share at the market price on the last day of each year or period reported. Dividends and distributions, if any, are assumed, for purposes of this calculation, to be reinvested at prices obtained under the Fund’s dividend reinvestment plan. Total investment return does not reflect brokerage commissions in connection with the purchase or sale of Fund shares.

(e)

Ratio includes interest expense primarily relates to participation in borrowing and financing transactions. See Note 5, Borrowings and Other Financing Transactions, in the Notes to Financial Statements for more information.

(f)

Fiscal year end changed from March 31st to June 30th.

(g)

Effective December 13, 2021, the Fund’s Investment advisory fee was decreased by 0.05% to an annual rate of 1.10%.

(h)

Total distributions for the period ended June 30, 2015 may be lower than prior fiscal years due to fiscal year end changes resulting in a reduction of the amount of days in the period ended June 30, 2015.

Base Prospectus

			Common Share			Ratios/Supplemental Data
							Ratios to Average Net Assets
Total	Increase resulting from Common Share Offering	Offering Cost Charged to Paid In Capital	Net Asset Value End of Year or Period(a)	Market Price End of Year or Period	Total Investment Return(d)	Net Assets Applicable to Common Shareholders (000s)	Expenses(e)	Expenses Excluding Waivers(e)	Expenses Excluding Interest Expenses	Expenses Excluding Interest Expense and Waivers	Net Investment Income (Loss)	Portfolio Turnover Rate

$(1.32)	$0.06	$0.00	$24.50	$25.91	(5.35)%	$5,401,430	2.46%*(g)	2.46%*(g)	2.01%*(g)	2.01%*(g)	11.18%*	21%
(2.65)	0.21	0.00	25.23	28.81	29.29	1,781,435	2.78	2.78	2.04	2.04	10.36	38
(3.07)	0.25	0.00	22.59	24.72	(14.18)	1,375,107	3.72	3.72	1.99	1.99	11.44	21
(3.15)	0.10	(0.00)	28.29	32.15	12.03	1,603,368	3.96	3.96	1.89	1.89	9.70	12
(2.65)	0.18	(0.00)	28.98	31.87	15.54	1,575,523	4.07	4.07	2.01	2.01	10.26	9
(4.10)	0.08	0.00	28.32	30.18	27.07	1,372,674	4.08	4.08	2.14	2.14	9.58	20
(5.24)	N/A	N/A	26.56	27.57	13.75	1,222,499	3.60	3.60	2.12	2.12	13.67	13
(0.63)(h)	N/A	N/A	31.38	29.21	2.87	1,426,891	2.83*	2.83*	2.01*	2.01*	10.23*	5
(4.13)	N/A	N/A	30.74	29.00	9.04	1,397,987	3.12	3.12	2.12	2.12	9.98	10
(3.52)	N/A	N/A	32.11	30.32	9.62	1,458,961	3.15	3.15	2.17	2.17	11.90	18
(2.45)	N/A	(0.03)	30.69	31.10	35.21	1,393,099	2.91*	2.91*	2.04*	2.04*	12.04*	16

June 23, 2022 | Base Prospectus 30

PIMCO Dynamic Income Fund

Use of Proceeds

The net proceeds of an offering will be invested in accordance with the Fund’s investment objectives and policies as set forth below. It is currently anticipated that the Fund will be able to invest substantially all of the net proceeds of an offering in accordance with its investment objectives and policies within approximately 30 days of receipt by the Fund, depending on the amount and timing of proceeds available to the Fund as well as the availability of investments consistent with the Fund’s investment objectives and policies, and except to the extent proceeds are held in cash to pay dividends or expenses, or for temporary defensive purposes. Pending such investment, it is anticipated that the proceeds of an offering will be invested in high grade, short-term securities, credit-linked trust certificates, and/or high yield securities index futures contracts or similar derivative instruments designed to give the Fund exposure to the securities and markets in which it intends to invest while the Investment Manager selects specific investments.

The Fund

The Fund is a diversified, closed-end management investment company. The Fund was organized as a Massachusetts business trust on January 19, 2011, pursuant to an Agreement and Declaration of Trust governed by the laws of the Commonwealth of Massachusetts. The Fund commenced operations on May 30, 2012, following the initial public offering of its Common Shares.

Investment Objectives and Policies

When used in this prospectus, the term “invest” includes both direct investing and indirect investing and the term “investments” includes both direct investments and indirect investments. For example, the Fund may invest indirectly by investing in derivatives or through its Subsidiaries (each, a “Subsidiary”, and collectively, the “Subsidiaries”). References herein to the Fund include, as appropriate, Subsidiaries through which the Fund may gain exposure to investments. The Fund may be exposed to the different types of investments described below through its investments in its Subsidiaries. The allocation of the Fund’s assets to a Subsidiary will vary over time and will likely not include all of the different types of investments described herein at any given time.

The Fund seeks current income as a primary objective and capital appreciation as a secondary objective. The Fund seeks to achieve its investment objectives by utilizing a dynamic asset allocation strategy among multiple fixed income sectors in the global credit markets, including corporate debt (including, among other things, fixed-, variable- and floating-rate bonds, bank loans, convertible securities and stressed debt securities issued by U.S. or foreign (non-U.S. and emerging market) corporations or other business entities), mortgage-related and other asset-backed securities, government and sovereign debt, taxable municipal bonds and other fixed-, variable- and floating-rate income-producing securities of U.S. and foreign issuers, including emerging market issuers. The Fund may invest in investment grade debt securities and below investment grade debt securities (commonly referred to as “high yield” securities or “junk bonds”), including securities of defaulted and stressed issuers. The types of securities and

instruments in which the Fund may invest are summarized under “Portfolio Contents” below. The Fund cannot assure you that it will achieve its investment objectives, and you could lose all of your investment in the Fund.

The Fund cannot change its investment objectives without the approval of the holders of a “majority of the outstanding” shares of the Fund. A “majority of the outstanding” shares (whether voting together as a single class or voting as a separate class) means (i) 67% or more of such shares present at a meeting, if the holders of more than 50% of those shares are present or represented by proxy, or (ii) more than 50% of such shares, whichever is less.

Portfolio Management Strategies

Dynamic Allocation Strategy. In managing the Fund, Pacific Investment Management Company LLC (“PIMCO” or the “Investment Manager”) employs an active approach to allocation among multiple fixed income sectors based on, among other things, market conditions, valuation assessments, economic outlook, credit market trends and other economic factors. With PIMCO’s macroeconomic analysis as the basis for top-down investment decisions, including geographic and credit sector emphasis, PIMCO manages the Fund with a focus on seeking income generating investment ideas across multiple fixed income sectors, with an emphasis on seeking opportunities in developed and emerging global credit markets. PIMCO may choose to focus on particular countries/regions, asset classes, industries and sectors to the exclusion of others at any time and from time to time based on market conditions and other factors. The relative value assessment within fixed income sectors draws on PIMCO’s regional and sector specialist expertise. As a matter of fundamental policy, the Fund will normally invest at least 25% of its total assets in privately-issued (commonly known as “non-agency”) mortgage-related securities. The Fund will observe various investment guidelines as summarized below.

PIMCO utilizes strategies that focus on credit quality analysis, duration management and other risk management techniques. PIMCO attempts to identify, through fundamental research driven by independent credit analysis and proprietary analytical tools, debt obligations and other income producing securities that provide current income and/or opportunities for capital appreciation based on its analysis of the issuer’s credit characteristics and the position of the security in the issuer’s capital structure.

Base Prospectus

of the issuer’s credit characteristics, forecast for interest rates and outlook for particular countries/regions, currencies, industries, sectors and the global economy and bond markets generally.

Credit Quality. The Fund may invest in debt instruments that are, at the time of purchase, rated below investment grade, or unrated but determined by PIMCO to be of comparable quality. However, the Fund will not normally invest more than 20% of its total assets in debt instruments, other than mortgage-related and other asset-backed securities, that are, at the time of purchase, rated CCC+ or lower by S&P and Fitch and Caa1 or lower by Moody’s, or that are unrated but determined by PIMCO to be of comparable quality to securities so rated. The Fund may invest without limitation in mortgage-related and other asset-backed securities regardless of rating—i.e., of any credit quality. For purposes of applying the foregoing policies, in the case of securities with split ratings (i.e., a security receiving two different ratings from two different rating agencies), the Fund will apply the higher of the applicable ratings. Subject to the aforementioned investment restrictions, the Fund may invest in securities of stressed issuers, which include securities at risk of being in default as to the repayment of principal and/or interest at the time of acquisition by the Fund or that are rated in the lower rating categories by one or more nationally recognized statistical rating organizations (for example, Ca or lower by Moody’s or CC or lower by S&P or Fitch) or, if unrated, are determined by PIMCO to be of comparable quality. Debt instruments of below investment grade quality are regarded as having predominantly speculative characteristics with respect to capacity to pay interest and to repay principal, and are commonly referred to as “high yield” securities or “junk bonds.” Debt instruments in the lowest investment grade category also may be considered to possess some speculative characteristics. The Fund may, for hedging, investment or leveraging purposes, make use of credit default swaps, which are contracts whereby one party makes periodic payments to a counterparty in exchange for the right to receive from the counterparty a payment equal to the par (or other agreed-upon) value of a referenced debt obligation in the event of a default or other credit event by the issuer of the debt obligation.

Independent Credit Analysis. PIMCO relies primarily on its own analysis of the credit quality and risks associated with individual debt instruments considered for the Fund, rather than relying exclusively on rating agencies or third-party research. The Fund’s portfolio managers utilize this information in an attempt to manage credit risk and to identify issuers, industries or sectors that are undervalued or that offer attractive yields relative to PIMCO’s assessment of their credit characteristics. This aspect of PIMCO’s capabilities will be particularly important to the extent that the Fund invests in high yield securities and in securities of emerging market issuers.

maturity or duration of any individual security in which the Fund may invest. Duration is a measure used to determine the sensitivity of a security’s price to changes in interest rates. The Fund’s duration strategy may entail maintaining a negative average portfolio duration from time to time, which would potentially benefit the portfolio in an environment of rising market interest rates, but would generally adversely impact the portfolio in an environment of falling or neutral market interest rates. PIMCO may also utilize certain strategies, including without limitation investments in structured notes or interest rate futures contracts or swap, cap, floor or collar transactions, for the purpose of reducing the interest rate sensitivity of the Fund’s portfolio, although there is no assurance that it will do so or that such strategies will be successful.

Portfolio Contents

The Fund normally invests worldwide in a portfolio of debt obligations and other income-producing securities of any type and credit quality, with varying maturities and related derivative instruments. The Fund’s portfolio of debt obligations and income-producing securities may include, without limitation, bonds, debentures, notes, and other debt securities of U.S. and foreign (non-U.S.) corporate and other issuers, including commercial paper; mortgage-related and other asset-backed securities issued by governmental agencies or other governmental entities or by private originators or issuers (including mortgage pass-through securities, collateralized mortgage obligations, adjustable rate mortgage-backed securities, stripped mortgage-backed securities, collateralized bond obligations, collateralized loan obligations and other collateralized debt obligations); U.S. Government securities; obligations of foreign governments or their sub-divisions, agencies and government sponsored enterprises and obligations of international agencies and supranational entities; municipal securities and other debt securities issued by states or local governments and their agencies, authorities and other government-sponsored enterprises, including taxable municipal securities (such as Build America Bonds); payment-in-kind securities; step-ups; zero-coupon bonds; inflation-indexed bonds issued by both governments and corporations; structured notes, including hybrid or indexed securities; catastrophe bonds and other event linked bonds; credit-linked notes; credit-linked trust instruments; structured credit products; bank loans (including, among others, senior loans, delayed funding loans, covenant-lite obligations, revolving credit facilities and loan participations and assignments); preferred securities; convertible debt securities (i.e., debt securities that may be converted at either a stated price or stated rate into underlying shares of common stock), including synthetic convertible debt securities (i.e., instruments created through a combination of separate securities that possess the two principal characteristics of a traditional convertible security, such as an income-producing security and the right to acquire an equity security) and contingent convertible securities; and bank certificates of deposit, fixed time deposits and bankers’ acceptances. The rate of interest on an income-producing security may be fixed, floating or variable, and may move in the opposite direction to interest rates generally or the interest rate on another security or index (i.e., inverse floaters). Certain corporate income-producing securities, such as convertible bonds, also may include the right to participate in equity

June 23, 2022 | Base Prospectus 32

PIMCO Dynamic Income Fund

appreciation. The Fund may invest in debt securities of stressed issuers. Subject to the investment limitations described under “Credit Quality” above, at any given time and from time to time, substantially all of the Fund’s portfolio may consist of below investment grade securities and/or mortgage-related or other types of asset backed securities. The Fund may invest in various levels of the capital structure of an issuer of mortgage-backed or asset-backed securities, including the equity or “first loss” tranche. The Fund may also invest, as a third party purchaser, in risk retention tranches of commercial mortgage-backed securities or other eligible securitizations, which are eligible residual interests typically held by the sponsors of such securitizations pursuant to the final rules implementing the credit risk retention requirements of Section 941 of the Dodd-Frank Act.

The Fund may invest without limitation in securities of U.S. issuers and without limitation in securities of foreign (non- U.S.) issuers, securities traded principally outside of the United States, and securities denominated in currencies other than the U.S. dollar. The Fund may invest without limitation in investment grade sovereign debt denominated in the relevant country’s local currency with less than one year remaining to maturity (“short-term investment grade sovereign debt”), including short-term investment grade sovereign debt issued by emerging market issuers. The Fund may invest up to 40% of its total assets in securities and instruments that are economically tied to “emerging market” countries, other than investments in short-term investment grade sovereign debt issued by emerging market issuers, where as noted above there is no limit. The Fund may also invest directly in foreign currencies, including local emerging market currencies.

As a matter of fundamental policy, the Fund normally invests at least 25% of its total assets in privately-issued (commonly known as “non-agency”) mortgage-related securities.

The Fund will not normally invest directly in common stocks of operating companies. However, the Fund may own and hold common stocks of operating companies in its portfolio from time to time in connection with a corporate action or the restructuring of a debt instrument, or through the conversion of a convertible security held by the Fund. Common stocks include common shares and other common equity interest issued by public or private issuers.

The Fund may invest in securities that have not been registered for public sale in the U.S. or relevant non-U.S. jurisdictions, including without limitation securities eligible for purchase and sale pursuant to Rule 144A under the Securities Act, or relevant provisions of applicable non-U.S. law, and other securities issued in private placements. The Fund may also invest in securities of other investment companies (including those advised by PIMCO), including without limitation, domestic and foreign exchange-traded funds (ETFs). The Fund may invest in REITs. The Fund may invest in securities of companies of any market capitalization, including small and medium capitalizations.

The Fund may make investments in debt instruments and other securities or instruments directly or through one or more Subsidiaries. Each Subsidiary may invest, for example, in whole loans or in shares, certificates, notes or other securities representing the right to receive principal and interest payments due on fractions of whole loans or pools of whole loans, or any other security or other instrument that the Fund may hold directly. References herein to the Fund include, as appropriate, Subsidiaries through which the Fund may gain exposure to investments. The Fund may be exposed to the different types of investments described below through its investments in its Subsidiaries. The allocation of the Fund’s assets to a Subsidiary will vary over time and will likely not include all of the different types of investments described herein at any given time.

Base Prospectus

When acquiring loans or purchasing Alt Lending ABS the Fund is not restricted by any particular borrower credit criteria. Accordingly, certain loans acquired by the Fund or underlying any Alt Lending ABS purchased by the Fund may be subprime in quality, or may become subprime in quality.

The Fund may enter into repurchase agreements, in which the Fund purchases a security from a bank or broker-dealer and the bank or broker-dealer agrees to repurchase the security at the Fund’s cost plus interest within a specified time.

For the purpose of achieving income, the Fund may lend its portfolio securities to brokers, dealers or other financial institutions provided a number of conditions are satisfied, including that the loan is fully collateralized.

The length of time the Fund has held a particular security is not generally a consideration in investment decisions. A change in the securities held by the Fund is known as “portfolio turnover.” The Fund may engage in frequent and active trading of portfolio securities to achieve its investment objectives, particularly during periods of volatile market movements.

Temporary Defensive Investments. Upon PIMCO’s recommendation for temporary defensive purposes or in order to keep its cash fully invested the Fund may deviate from its investment strategy by investing some or all of its total assets in investments such as high grade debt securities, including high quality, short-term debt securities, and cash and cash equivalents. The Fund may not achieve its investment objectives when it does so.

The following provides additional information regarding the types of securities and other instruments in which the Fund will ordinarily invest. A more detailed discussion of these and other instruments and investment techniques that may be used by the Fund is provided under “Investment Objectives and Policies” in the Statement of Additional Information.

High Yield Securities

The Fund may invest without limitation in debt instruments that are, at the time of purchase, rated below investment grade (below Baa3 by Moody’s or below BBB- by either S&P or Fitch) or unrated but determined by PIMCO to be of comparable quality. However, the Fund will not normally invest more than 20% of its total assets in debt instruments, other than mortgage-related and other asset-backed instruments, that are, at the time of purchase, rated CCC+ or lower by S&P and Fitch and Caa1 or lower by Moody’s, or that are unrated but

determined by PIMCO to be of comparable quality to securities so rated. The Fund may invest in mortgage-related and other asset-backed securities regardless of rating (i.e., of any credit quality). For purposes of applying the foregoing policies, in the case of securities with split ratings (i.e., a security receiving two different ratings from two different rating agencies), the Fund will apply the higher of the applicable ratings. Subject to the aforementioned investment restrictions, the Fund may invest in debt securities of stressed or distressed issuers, which include securities at risk of being in default as to the repayment of principal and/or interest at the time of acquisition by the Fund or that are rated in the lower rating categories by one or more nationally recognized statistical rating organizations(for example, Ca or lower by Moody’s or CC or lower by S&P or Fitch) or, if unrated, are determined by PIMCO to be of comparable quality. The Fund may also invest in defaulted securities and debtor-in-possession financings (commonly known as “DIP financings”). Below investment grade securities are commonly referred to as “high yield” securities or “junk bonds.” High yield securities involve a greater degree of risk (in particular, a greater risk of default) than, and special risks in addition to the risks associated with, investment grade debt obligations. While offering a greater potential opportunity for capital appreciation and higher yields, high yield securities typically entail greater potential price volatility and may be less liquid than higher-rated securities. High yield securities may be regarded as predominantly speculative with respect to the issuer’s continuing ability to make timely principal and interest payments. They also may be more susceptible to real or perceived adverse economic and competitive industry conditions than higher-rated securities. Debt securities in the lowest investment grade category also may be considered to possess some speculative characteristics by certain ratings agencies.

The market values of high yield securities tend to reflect individual developments of the issuer to a greater extent than do higher-quality securities, which tend to react mainly to fluctuations in the general level of interest rates. In addition, lower-quality debt securities tend to be more sensitive to general economic conditions. Certain emerging market governments that issue high yield securities in which the Fund may invest are among the largest debtors to commercial banks, foreign governments and supranational organizations, such as the World Bank, and may not be able or willing to make principal and/or interest payments as they come due.

Credit ratings and unrated securities. Rating agencies are private services that provide ratings of the credit quality of debt obligations. Appendix A to this prospectus describes the various ratings assigned to debt obligations by Moody’s, S&P and Fitch. As noted in Appendix A, Moody’s, S&P and Fitch may modify their ratings of securities to show relative standing within a rating category, with the addition of numerical modifiers (1, 2 or 3) in the case of Moody’s, and with the addition of a plus (+) or minus (-) sign in the case of S&P and Fitch. Ratings assigned by a rating agency are not absolute standards of credit quality and do not evaluate market risks. Rating agencies may fail to make timely changes in credit ratings and an issuer’s current financial condition may be better or worse than a rating indicates. The Fund will not necessarily sell a security when its rating is reduced below its rating

June 23, 2022 | Base Prospectus 34

PIMCO Dynamic Income Fund

at the time of purchase. The ratings of a debt security may change over time. Moody’s, S&P and Fitch monitor and evaluate the ratings assigned to securities on an ongoing basis. As a result, debt instruments held by the Fund could receive a higher rating (which would tend to increase their value) or a lower rating (which would tend to decrease their value) during the period in which they are held by the Fund.

The Fund may purchase unrated securities (which are not rated by a rating agency) if PIMCO determines, in its sole discretion, that the security is of comparable quality to a rated security that the Fund may purchase. In making these determinations, PIMCO may take into account different factors than those taken into account by rating agencies, and PIMCO’s rating of a security may differ from the rating that a rating agency may have given the same security. Unrated securities may be less liquid than comparable rated securities and involve the risk that the portfolio manager may not accurately evaluate the security’s comparative credit rating. The Fund may invest a substantial portion of its assets in unrated securities and therefore may be particularly subject to the associated risks. Analysis of the creditworthiness of issuers of high yield securities may be more complex than for issuers of higher-quality fixed income securities. To the extent that the Fund invests in high yield and/or unrated securities, the Fund’s success in achieving its investment objectives may depend more heavily on the portfolio manager’s creditworthiness analysis than if the Fund invested exclusively in higher-quality and higher-rated securities.

Foreign (Non-U.S.) Investments

Subject to the limit described elsewhere in this prospectus on investments in securities and instruments that are economically tied to “emerging market” countries, the Fund may invest without limitation in instruments of corporate and other foreign (non-U.S.) issuers, and in instruments traded principally outside of the United States. The Fund may invest in sovereign and other debt securities issued by foreign governments and their respective sub-divisions, agencies or instrumentalities, government sponsored enterprises and supranational government entities. Supranational entities include international organizations that are organized or supported by one or more government entities to promote economic reconstruction or development and by international banking institutions and related governmental agencies. As a holder of such debt securities, the Fund may be requested to participate in the rescheduling of such debt and to extend further loans to governmental entities. In addition, there are generally no bankruptcy proceedings similar to those in the United States by which defaulted foreign debt securities may be collected. Investing in foreign securities involves special risks and considerations not typically associated with investing in U.S. securities. See “Principal Risks of the Fund—Foreign (Non-U.S.) Investment Risk.”

PIMCO generally considers an instrument to be economically tied to a non- U.S. country if the issuer is a foreign (non-U.S.) government (or any political subdivision, agency, authority or instrumentality of such government), or if the issuer is organized under the laws of a non-U.S. country. In the case of money market instruments other than commercial paper and certificates of deposit, such instruments will be considered economically tied to a non-U.S. country if the issuer of such

money market instrument is organized under the laws of a non-U.S. country. In the case of commercial paper and certificates of deposit, instruments will be considered economically tied to a non-U.S. country if the “country of exposure” of such instrument is a non-U.S. country, as determined by the criteria set forth below. With respect to derivative instruments, PIMCO generally considers such instruments to be economically tied to non-U.S. countries if the underlying assets are foreign currencies (or baskets or indexes of such currencies), or instruments or securities that are issued by foreign governments or issuers organized under the laws of a non-U.S. country (or if the underlying assets are money market instruments, other than commercial paper and certificates of deposit, the issuer of such money market instrument is organized under the laws of a non-U.S. country or, in the case of underlying assets that are commercial paper or certificates of deposit, if the “country of exposure” of such money market instrument is a non-U.S. country). A security’s “country of exposure” will be determined by PIMCO using certain factors provided by a third-party analytical service provider. The factors are applied in order such that the first factor to result in the assignment of a country determines the “country of exposure.” Both the factors and the order in which they are applied may change in the discretion of PIMCO. The current factors, listed in the order in which they are applied, are: (i) if an asset-backed or other collateralized security, the country in which the collateral backing the security is located; (ii) the “country of risk” of the issuer; (iii) if the security is guaranteed by the government of a country (or any political subdivision, agency, authority or instrumentality of such government), the country of the government or instrumentality providing the guarantee; (iv) the “country of risk” of the issuer’s ultimate parent; or (v) the country where the issuer is organized or incorporated under the laws thereof. “Country of risk” is a separate four-part test determined by the following factors, listed in order of importance: (i) management location; (ii) country of primary listing; (iii) sales or revenue attributable to the country; and (iv) reporting currency of the issuer.

The Fund may invest in Brady Bonds, which are securities created through the exchange of existing commercial bank loans to sovereign entities for new obligations in connection with a debt restructuring. Investments in Brady Bonds may be viewed as speculative. Brady Bonds acquired by the Fund may be subject to restructuring arrangements or to requests for new credit, which may cause the Fund to realize a loss of interest or principal on any of its portfolio holdings.

The foreign securities in which the Fund may invest include, without limitation, Eurodollar obligations and “Yankee Dollar” obligations. Eurodollar obligations are U.S. dollar-denominated certificates of deposit and time deposits issued outside the U.S. capital markets by foreign branches of U.S. banks and by foreign banks. Yankee Dollar obligations are U.S. dollar-denominated obligations issued in the U.S. capital markets by foreign banks. Eurodollar and Yankee Dollar obligations are generally subject to the same risks that apply to domestic debt issues, notably credit risk, interest rate risk, market risk and liquidity risk. Additionally, Eurodollar (and to a limited extent, Yankee Dollar) obligations are subject to certain sovereign risks. One such risk is the possibility that a sovereign country might prevent capital, in the form of U.S. dollars, from flowing across its borders. Other

Base Prospectus

risks include adverse political and economic developments; the extent and quality of government regulation of financial markets and institutions; the imposition of foreign withholding or other taxes; and the expropriation or nationalization of foreign issuers; or the imposition of sanctions or other similar measures..

Emerging Markets Investments

The Fund may invest without limitation in short-term investment grade sovereign debt, including short-term investment grade sovereign debt issued by emerging market issuers. The Fund may invest up to 40% of its total assets in securities and instruments that are economically tied to “emerging market” countries other than investments in short-term investment grade sovereign debt issued by emerging market issuers, where as noted above there is no limit. PIMCO generally considers an instrument to be economically tied to an emerging market country if: the issuer is organized under the laws of an emerging market country; the currency of settlement of the security is a currency of an emerging market country; the security is guaranteed by the government of an emerging market country (or any political subdivision, agency, authority or instrumentality of such government); for an asset-backed or other collateralized security, the country in which the collateral backing the security is located is an emerging market country; or the security’s “country of exposure” is an emerging market country, as determined by the criteria set forth below. With respect to derivative instruments, PIMCO generally considers such instruments to be economically tied to emerging market countries if the underlying assets are currencies of emerging market countries (or baskets or indexes of such currencies), or instruments or securities that are issued or guaranteed by governments of emerging market countries or by entities organized under the laws of emerging market countries or an instrument’s “country of exposure” is an emerging market country. PIMCO has broad discretion to identify countries that it considers to qualify as emerging markets. In exercising such discretion, PIMCO identifies countries as emerging markets consistent with the strategic objectives of the Fund. For example, the Fund may consider a country to be an emerging market country based on a number of factors including, but not limited to, if the country is classified as an emerging or developing economy by any supranational organization such as the World Bank or the United Nations, or related entities, or if the country is considered an emerging market country for purposes of constructing emerging markets indices. In some cases, this approach may result in PIMCO identifying a particular country as an emerging market with respect to the Fund, that may not be identified as an emerging market with respect to other funds managed by PIMCO.

Investing in emerging market securities imposes risks different from, or greater than, risks of investing in domestic securities or in foreign developed countries. The securities and currency markets of emerging market countries are generally smaller, less developed, less liquid, and more volatile than the securities and currency markets of the United States and other developed markets and disclosure and regulatory standards in many respects are less stringent. There also may be a lower level of monitoring and regulation of securities markets in emerging market countries and the activities of investors in such markets and enforcement of existing regulations may be extremely

limited. Government enforcement of existing securities regulations is limited, and any enforcement may be arbitrary and the results may be difficult to predict. In addition, reporting requirements of emerging market countries with respect to the ownership of securities are more likely to be subject to interpretation or changes without prior notice to investors than more developed countries.

Many emerging market countries have experienced substantial, and in some periods extremely high, rates of inflation for many years. Inflation and rapid fluctuations in inflation rates have had and may continue to have negative effects on such countries’ economies and securities markets.

Economies of emerging market countries generally are heavily dependent upon international trade and, accordingly, have been and may continue to be affected adversely by trade barriers, exchange controls, managed adjustments in relative currency values, and other protectionist measures imposed or negotiated by the countries with which they trade. The economies of emerging market countries also have been and may continue to be adversely affected by economic conditions in the countries with which they trade. The economies of emerging market countries may also be predominantly based on only a few industries or dependent on revenues from particular commodities. In addition, custodial services and other investment-related costs may be more expensive in emerging markets than in many developed markets, which could reduce the Fund’s income from securities or debt instruments of emerging market country issuers. Governments of many emerging market countries have exercised and continue to exercise substantial influence over many aspects of the private sector. In some cases, the government owns or controls many companies, including some of the largest in the country. Accordingly, government actions could have a significant effect on economic conditions in an emerging market country and on market conditions, prices and yields of securities in the Fund’s portfolio.

Emerging market countries are more likely than developed market countries to experience political uncertainty and instability, including the risk of war, terrorism, nationalization, limitations on the removal of funds or other assets, or diplomatic developments that affect investments in these countries. No assurance can be given that adverse political changes will not cause the Fund to suffer a loss of any or all of its investments in emerging market countries or interest/dividend income thereon.

Foreign investment in certain emerging market country securities is restricted or controlled to varying degrees. These restrictions or controls may at times limit or preclude foreign investment in certain emerging market country securities and increase the costs and expenses of the Fund. Certain emerging market countries require governmental approval prior to investments by foreign persons, limit the amount of investment by foreign persons in a particular issuer, limit the investment by foreign persons only to a specific class of securities of an issuer that may have less advantageous rights than the classes available for purchase by domiciliaries of the countries and/or impose additional taxes on foreign investors. Certain emerging market countries may also restrict investment opportunities in issuers in industries deemed important to

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national interests. Emerging market countries may require governmental approval for the repatriation of investment income, capital or the proceeds of sales of securities by foreign investors.

Also, because publicly traded debt instruments of emerging market issuers represent a relatively recent innovation in the world debt markets, there is little historical data or related market experience concerning the attributes of such instruments under all economic, market and political conditions.

As reflected in the above discussion, investments in emerging market securities involve a greater degree of risk than, and special risks in addition to the risks associated with, investments in domestic securities or in securities of foreign developed countries. See “Principal Risks of the Fund—Emerging Markets Risk.”

Foreign Currencies and Related Transactions

The Fund’s Common Shares are priced in U.S. dollars and the distributions paid by the Fund to Common Shareholders are paid in U.S. dollars. However, a significant portion of the Fund’s assets may be denominated in foreign (non-U.S.) currencies and the income received by the Fund from many foreign debt obligations will be paid in foreign currencies. The Fund also may invest in or gain exposure to foreign currencies themselves for investment or hedging purposes. The Fund’s investments in securities that trade in, or receive revenues in, foreign currencies will be subject to currency risk, which is the risk that fluctuations in the exchange rates between the U.S. dollar and foreign currencies may negatively affect the value of an investment. See “Principal Risks of the Fund—Currency Risk.” The Fund may (but is not required to) hedge some or all of its exposure to foreign currencies through the use of derivative strategies. For instance, the Fund may enter into forward foreign currency exchange contracts, and may buy and sell foreign currency futures contracts and options on foreign currencies and foreign currency futures. A forward foreign currency exchange contract, which involves an obligation to purchase or sell a specific currency at a future date at a price set at the time of the contract, may reduce the Fund’s exposure to changes in the value of the currency it will deliver and increase its exposure to changes in the value of the currency it will receive for the duration of the contract. The effect on the value of the Fund’s assets is similar to selling securities denominated in one currency and purchasing securities denominated in another currency. Foreign currency transactions, like currency exchange rates, can be affected unpredictably by intervention (or the failure to intervene) by U.S. or foreign governments or central banks, or by currency controls or political developments. Such events may prevent or restrict the Fund’s ability to enter into foreign currency transactions, force the Fund to exit a foreign currency transaction at a disadvantageous time or price or result in penalties for the Fund, any of which may result in a loss to the Fund.

Contracts to sell foreign currency would limit any potential gain that might be realized by the Fund if the value of the hedged currency increases. The Fund may enter into these contracts to hedge against foreign exchange risk arising from the Fund’s investment or anticipated investment in securities denominated in foreign currencies. Suitable

hedging transactions may not be available in all circumstances and there can be no assurance that the Fund will engage in such transactions at any given time or from time to time when they would be beneficial. Although PIMCO has the flexibility to engage in such transactions for the Fund, it may determine not to do so or to do so only in unusual circumstances or market conditions. Also, these transactions may not be successful and may eliminate any chance for the Fund to benefit from favorable fluctuations in relevant foreign currencies.

The Fund may also use derivatives contracts for purposes of increasing exposure to a foreign currency or to shift exposure to foreign currency fluctuations from one currency to another. To the extent that it does so, the Fund will be subject to the additional risk that the relative value of currencies will be different than anticipated by PIMCO.

Please see “Investment Objectives and Policies—Non-U.S. Securities,” “Investment Objectives and Policies— Foreign Currency Transactions” and “Investment Objectives and Policies—Foreign Currency Exchange-Related Securities” in the Statement of Additional Information for a more detailed description of the types of foreign investments and foreign currency transactions in which the Fund may invest or engage and their related risks.

Mortgage-Related and Other Asset-Backed Instruments

The Fund may invest in a variety of mortgage-related and other asset-backed instruments issued by government agencies or other governmental entities or by private originators or issuers.

As a matter of fundamental policy, the Fund normally invests at least 25% of its total assets (i.e., concentrate) in privately-issued (commonly known as “non-agency”) mortgage-related securities.

Mortgage-related securities include mortgage pass-through securities, CMOs, commercial mortgage-backed securities (“CMBSs”), residential mortgage-backed securities, mortgage dollar rolls/buy backs, CMO residuals, adjustable rate mortgage-backed securities (“ARMs”), SMBSs and other securities that directly or indirectly represent a participation in, or are secured by and payable from, mortgage loans on real property.

Mortgage Pass-Through Securities. Interests in pools of mortgage-related securities differ from other forms of debt securities, which normally provide for periodic payment of interest in fixed amounts with principal payments at maturity or specified call dates. Instead, these securities provide a monthly payment which consists of both interest and principal payments. In effect, these payments are a “pass through” of the monthly payments made by the individual borrowers on their residential or commercial mortgage loans, net of any fees paid to the issuer, servicer or guarantor of such securities. Additional payments may result from repayments of principal resulting from the sale of the underlying property, refinancing or foreclosure, net of fees or costs that may be incurred. Some mortgage-related securities (such as securities issued by GNMA) are described as “modified pass-through.” These securities entitle the holder to receive all interest and principal payments owed on the mortgage pool, net of certain fees, at the scheduled payment dates regardless of whether or not the mortgagor actually makes the payment.

Base Prospectus

The rate of pre-payments on underlying mortgages will affect the price and volatility of a mortgage-related security, and may have the effect of shortening or extending the effective duration of the security relative to what was anticipated at the time of purchase. To the extent that unanticipated lower rates of pre-payment on underlying mortgages increase the effective duration of a mortgage-related security, the volatility of such security can be expected to increase. The residential mortgage market in the United States has experienced in the past, and could experience in the future, difficulties that may adversely affect the performance and market value of certain of the Fund’s mortgage-related investments. Delinquencies, defaults and losses on residential mortgage loans may increase substantially over certain periods. A decline in or flattening of housing values may exacerbate such delinquencies and losses on residential mortgages. Borrowers with adjustable rate mortgage loans are more sensitive to changes in interest rates, which affect their monthly mortgage payments, and may be unable to secure replacement mortgages at comparably low interest rates. As a result of the 2008 financial crisis, a number of residential mortgage loan originators experienced serious financial difficulties or bankruptcy. Owing largely to the foregoing, reduced investor demand for mortgage loans and mortgage-related securities and increased investor yield requirements caused limited liquidity in the secondary market for certain mortgage-related securities, which adversely affected the market value of mortgage-related securities. It is possible that such limited liquidity in such secondary markets could recur or worsen in the future.

The principal U.S. governmental guarantor of mortgage-related securities is GNMA. GNMA is a wholly owned U.S. government corporation within the Department of Housing and Urban Development. GNMA is authorized to guarantee, with the full faith and credit of the U.S. government, the timely payment of principal and interest on securities issued by institutions approved by GNMA (such as savings and loan institutions, commercial banks and mortgage bankers) and backed by pools of mortgages insured by the Federal Housing Administration (the “FHA”), or guaranteed by the Department of Veterans Affairs (the “VA”). Government-related guarantors (i.e., not backed by the full faith and credit of the U.S. government) include FNMA and FHLMC. FNMA is a government-sponsored corporation the common stock of which is owned entirely by private stockholders. FNMA purchases conventional (i.e., not insured or guaranteed by any government agency) residential mortgages from a list of approved seller/servicers which include state and federally chartered savings and loan associations, mutual savings banks, commercial banks and credit unions and mortgage bankers. Pass-through securities issued by FNMA are guaranteed as to timely payment of principal and interest by FNMA, but are not backed by the full faith and credit of the U.S. government. FHLMC was created by Congress in 1970 for the purpose of increasing the availability of mortgage credit for residential housing. It is a government-sponsored corporation that issues Participation Certificates (“PCs”), which are pass-through securities, each representing an undivided interest in a pool of residential mortgages. FHLMC guarantees the timely payment of interest and ultimate collection of

principal, but PCs are not backed by the full faith and credit of the U.S. government. Instead, they are supported only by the discretionary authority of the U.S. government to purchase the agency’s obligations.

On September 6, 2008, the Federal Housing Finance Agency (“FHFA”) placed FNMA and FHLMC into conservatorship. As the conservator, FHFA succeeded to all rights, titles, powers and privileges of FNMA and FHLMC and of any stockholder, officer or director of FNMA and FHLMC with respect to FNMA and FHLMC and the assets of FNMA and FHLMC. FHFA selected a new chief executive officer and chairman of the board of directors for each of FNMA and FHLMC. In connection with the conservatorship, the U.S. Treasury entered into a Senior Preferred Stock Purchase Agreement with each of FNMA and FHLMC pursuant to which the U.S. Treasury will purchase up to an aggregate of $100 billion of each of FNMA and FHLMC to maintain a positive net worth in each enterprise. This agreement contains various covenants that severely limit each enterprise’s operations. In exchange for entering into these agreements, the U.S. Treasury received $1 billion of each enterprise’s senior preferred stock and warrants to purchase 79.9% of each enterprise’s common stock. On February 18, 2009, the U.S. Treasury announced that it was doubling the size of its commitment to each enterprise under the Senior Preferred Stock Program to $200 billion. The U.S. Treasury’s obligations under the Senior Preferred Stock Program are for an indefinite period of time for a maximum amount of $200 billion per enterprise. On December 24, 2009, the U.S. Treasury announced further amendments to the Senior Preferred Stock Purchase Agreements which included additional financial support to certain governmentally supported entities, including the FHLBs, FNMA and FHLMC. There is no assurance that the obligations of such entities will be satisfied in full, or that such obligations will not decrease in value or default. It is difficult, if not impossible, to predict the future political, regulatory or economic changes that could impact the FNMA, FHLMC and the FHLBs, and the values of their related securities or obligations.

FNMA and FHLMC are continuing to operate as going concerns while in conservatorship and each remain liable for all of its obligations, including its guaranty obligations, associated with its mortgage-backed securities. Under the Federal Housing Finance Regulatory Reform Act of 2008 (the “Reform Act”), which was included as part of the Housing and Economic Recovery Act of 2008, FHFA, as conservator or receiver, has the power to repudiate any contract entered into by FNMA or FHLMC prior to FHFA’s appointment as conservator or receiver, as applicable, if FHFA determines, in its sole discretion, that performance of the contract is burdensome and that repudiation of the contract promotes the orderly administration of FNMA’s or FHLMC’s affairs. The Reform Act requires FHFA to exercise its right to repudiate any contract within a reasonable period of time after its appointment as conservator or receiver. FHFA, in its capacity as conservator, has indicated that it has no intention to repudiate the guaranty obligations of FNMA or FHLMC because FHFA views repudiation as incompatible with the goals of the conservatorship. However, in the event that FHFA, as conservator or if it is later appointed as receiver for FNMA or FHLMC, were to repudiate any such guaranty obligation, the conservatorship or receivership estate, as applicable, would be liable for actual direct compensatory damages in accordance with the provisions of the Reform Act. Any such liability

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could be satisfied only to the extent of FNMA’s or FHLMC’s assets available therefor. In the event of repudiation, the payments of interest to holders of FNMA or FHLMC mortgage-backed securities would be reduced if payments on the mortgage loans represented in the mortgage loan groups related to such mortgage-backed securities are not made by the borrowers or advanced by the servicer. Any actual direct compensatory damages for repudiating these guaranty obligations may not be sufficient to offset any shortfalls experienced by such mortgage-backed security holders. Further, in its capacity as conservator or receiver, FHFA has the right to transfer or sell any asset or liability of FNMA or FHLMC without any approval, assignment or consent. Although FHFA has stated that it has no present intention to do so, if FHFA, as conservator or receiver, were to transfer any such guaranty obligation to another party, holders of FNMA or FHLMC mortgage-backed securities would have to rely on that party for satisfaction of the guaranty obligation and would be exposed to the credit risk of that party. In addition, certain rights provided to holders of mortgage-backed securities issued by FNMA and FHLMC under the operative documents related to such securities may not be enforced against FHFA, or enforcement of such rights may be delayed, during the conservatorship or any future receivership. The operative documents for FNMA and FHLMC mortgage-backed securities may provide (or with respect to securities issued prior to the date of the appointment of the conservator may have provided) that upon the occurrence of an event of default on the part of FNMA or FHLMC, in its capacity as guarantor, which includes the appointment of a conservator or receiver, holders of such mortgage-backed securities have the right to replace FNMA or FHLMC as trustee if the requisite percentage of mortgage-backed securities holders consent. The Reform Act prevents mortgage-backed security holders from enforcing such rights if the event of default arises solely because a conservator or receiver has been appointed. The Reform Act also provides that no person may exercise any right or power to terminate, accelerate or declare an event of default under certain contracts to which FNMA or FHLMC is a party, or obtain possession of or exercise control over any property of FNMA or FHLMC, or affect any contractual rights of FNMA or FHLMC, without the approval of FHFA, as conservator or receiver, for a period of 45 or 90 days following the appointment of FHFA as conservator or receiver, respectively.

In June 2019, under the Single Security Initiative, FNMA and FHLMC started issuing a uniform mortgage-backed security in place of their current offerings of to-be-announced (“TBA”) eligible securities. The Single Security Initiative seeks to support the overall liquidity of the TBA market and aligns the characteristics of FNMA and FHLMC certificates. The effects that the Single Security Initiative may have on the market for TBA and other mortgage backed securities are uncertain.

Privately-Issued Mortgage-Related Securities. Commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers also create pass-through pools of conventional residential mortgage loans. Such issuers may be the originators and/or servicers of the underlying mortgage loans as well as the guarantors of the mortgage-related securities. Pools created by such non-governmental issuers generally

offer a higher rate of interest than government and government-related pools because there are no direct or indirect government or agency guarantees of payments in the former pools. However, timely payment of interest and principal of these pools may be supported by various forms of insurance or guarantees, including individual loan, title, pool and hazard insurance and letters of credit, which may be issued by governmental entities or private insurers. Such insurance and guarantees and the creditworthiness of the issuers thereof will be considered in determining whether a mortgage-related security meets the Fund’s investment quality standards. There can be no assurance that insurers or guarantors can meet their obligations under the insurance policies or guarantee arrangements. Securities issued by certain private organizations may not be readily marketable.

Privately-issued mortgage-related securities are not subject to the same underwriting requirements for the underlying mortgages that are applicable to those mortgage-related securities that have a government or government-sponsored entity guarantee. As a result, the mortgage loans underlying privately-issued mortgage-related securities may, and frequently do, have less favorable collateral, credit risk or other underwriting characteristics than government or government-sponsored mortgage-related securities and have wider variances in a number of terms including interest rate, term, size, purpose and borrower characteristics. Mortgage pools underlying privately-issued mortgage-related securities more frequently include second mortgages, high loan-to-value ratio mortgages and manufactured housing loans, in addition to commercial mortgages and other types of mortgages where a government or government-sponsored entity guarantee is not available. The coupon rates and maturities of the underlying mortgage loans in a privately-issued mortgage-related securities pool may vary to a greater extent than those included in a government guaranteed pool, and the pool may include subprime mortgage loans. Subprime loans are loans made to borrowers with weakened credit histories or with a lower capacity to make timely payments on their loans. For these reasons, the loans underlying these securities have had in many cases higher default rates than those loans that meet government underwriting requirements.

The risk of non-payment is greater for mortgage-related securities that are backed by loans that were originated under weak underwriting standards, including loans made to borrowers with limited means to make repayment. When acquiring mortgage-related securities, the Fund is not restricted by any particular borrower credit criteria. A level of risk exists for all loans, although, historically, the poorest performing loans have been those classified as subprime. Other types of privately-issued mortgage-related securities, such as those classified as pay-option adjustable rate or Alt-A have also performed poorly. Even loans classified as prime have experienced higher levels of delinquencies and defaults. The substantial decline in real property values across the United States following the 2008 financial crisis has exacerbated the level of losses that investors in privately issued mortgage-related securities have experienced. It is not certain when these trends may reverse. Market factors that may adversely affect mortgage loan repayment include adverse economic conditions, unemployment, a decline in the value of real property, or an increase in interest rates.

Base Prospectus

The Fund may purchase privately-issued mortgage-related securities that are originated, packaged and serviced by third party entities. It is possible these third parties could have interests that are in conflict with the holders of mortgage-related securities, and such holders (such as the Fund) could have rights against the third parties or their affiliates. For example, if a loan originator, servicer or its affiliates engaged in negligence or willful misconduct in carrying out its duties, then a holder of the mortgage-related security could seek recourse against the originator/servicer or its affiliates, as applicable. Also, as a loan originator/servicer, the originator/servicer or its affiliates may make certain representations and warranties regarding the quality of the mortgages and properties underlying a mortgage-related security. If one or more of those representations or warranties is false, then the holders of the mortgage-related securities (such as the Fund) could trigger an obligation of the originator/servicer or its affiliates, as applicable, to repurchase the mortgages from the issuing trust.

Notwithstanding the foregoing, many of the third parties that are legally bound by trust and other documents have failed to perform their respective duties, as stipulated in such trust and other documents, and investors have had limited success in enforcing terms. To the extent third party entities involved with privately issued mortgage-related securities are involved in litigation relating to the securities, actions may be taken that are adverse to the interests of holders of the mortgage-related securities, including the Fund. For example, third parties may seek to withhold proceeds due to holders of the mortgage-related securities, including the Fund, to cover legal or related costs. Any such action could result in losses to the Fund.

PIMCO seeks to manage the portion of the Fund’s assets committed to privately-issued mortgage-related securities in a manner consistent with the Fund’s investment objectives, policies and overall portfolio risk profile. In determining whether and how much to invest in privately-issued mortgage-related securities, and how to allocate those assets, PIMCO will consider a number of factors. These may include, but are not limited to: (1) the nature of the borrowers (e.g., residential vs. commercial); (2) the collateral loan type (e.g., for residential: First Lien - Jumbo/Prime, First Lien - Alt-A, First Lien - Subprime, First Lien - Pay-Option or Second Lien; for commercial: Conduit, Large Loan or Single Asset / Single Borrower); and (3) in the case of residential loans, whether they are fixed rate or adjustable mortgages. Each of these criteria can cause privately-issued mortgage-related securities to have differing primary economic characteristics and distinguishable risk factors and performance characteristics.

Collateralized Mortgage Obligations. A CMO is a debt obligation of a legal entity that is collateralized by mortgages and divided into classes. Similar to a bond, interest and prepaid principal is paid, in most cases, on a monthly basis. CMOs may be collateralized by whole mortgage loans or private mortgage bonds, but are generally collateralized by portfolios of mortgage pass-through securities guaranteed by GNMA, FHLMC or FNMA and their income streams. CMOs are structured into multiple classes, often referred to as “tranches,” with each class bearing a different stated maturity and entitled to a different schedule for payments of principal and interest,

including prepayments. The riskiest portion is the “equity” tranche which bears the bulk of defaults and serves to protect the other, more senior tranches from default in all but the most severe circumstances. Actual maturity and average life will depend upon the pre-payment experience of the collateral. In the case of certain CMOs (known as “sequential pay” CMOs), payments of principal received from the pool of underlying mortgages, including prepayments, are applied to the classes of CMOs in the order of their respective final distribution dates. Thus, no payment of principal will be made to any class of sequential pay CMOs until all other classes having an earlier final distribution date have been paid in full. CMOs may be less liquid and may exhibit greater price volatility than other types of mortgage- or asset-backed securities.

Commercial Mortgage-Backed Securities. CMBSs include securities that reflect an interest in, and are secured by, mortgage loans on commercial real property. Many of the risks of investing in commercial mortgage-backed securities reflect the risks of investing in the real estate securing the underlying mortgage loans. These risks reflect the effects of local and other economic conditions on real estate markets, the ability of tenants to make loan payments and the ability of a property to attract and retain tenants. Commercial or residential mortgage-backed securities may be less liquid and exhibit greater price volatility than other types of mortgage- or asset-backed securities.

CMO Residuals. CMO residuals are mortgage securities issued by agencies or instrumentalities of the U.S. Government or by private originators of, or investors in, mortgage loans, including savings and loan associations, homebuilders, mortgage banks, commercial banks, investment banks and special purpose entities of the foregoing. The cash flow generated by the mortgage assets underlying a series of a CMO is applied first to make required payments of principal and interest on the CMO and second to pay the related administrative expenses and any management fee of the issuer. The residual in a CMO structure generally represents the interest in any excess cash flow remaining after making the foregoing payments. Each payment of such excess cash flow to a holder of the related CMO residual represents income and/or a return of capital. The amount of residual cash flow resulting from a CMO will depend on, among other things, the characteristics of the mortgage assets, the coupon rate of each class of CMO, prevailing interest rates, the amount of administrative expenses and the prepayment experience on the mortgage assets. In particular, the yield to maturity on CMO residuals is extremely sensitive to prepayments on the related underlying mortgage assets, in the same manner as an interest-only (or IO) class of stripped mortgage-backed securities (described below). In addition, if a series of a CMO includes a class that bears interest at an adjustable rate, the yield to maturity on the related CMO residual will also be extremely sensitive to changes in the level of the index upon which interest rate adjustments are based. As described below with respect to stripped mortgage-backed securities, in certain circumstances the Fund may fail to recoup fully its initial investment in a CMO residual. CMO residuals are generally purchased and sold by institutional investors through several investment banking firms acting as brokers or dealers. CMO residuals may, or pursuant to an exemption therefrom, may not, have been registered under the Securities Act. CMO residuals,

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PIMCO Dynamic Income Fund

whether or not registered under the Securities Act, may be subject to certain restrictions on transferability.

Adjustable Rate Mortgage-Backed Securities. ARMs have interest rates that reset at periodic intervals. Acquiring ARMs permits the Fund to participate in increases in prevailing current interest rates through periodic adjustments in the coupons of mortgages underlying the pool on which ARMs are based. Such ARMs generally have higher current yield and lower price fluctuations than is the case with more traditional fixed income debt securities of comparable rating and maturity. In addition, when prepayments of principal are made on the underlying mortgages during periods of rising interest rates, the Fund can reinvest the proceeds of such prepayments at rates higher than those at which they were previously invested. Mortgages underlying most ARMs, however, have limits on the allowable annual or lifetime increases that can be made in the interest rate that the mortgagor pays. Therefore, if current interest rates rise above such limits over the period of the limitation, the Fund, when holding an ARM, does not benefit from further increases in interest rates. Moreover, when interest rates are in excess of coupon rates (i.e., the rates being paid by mortgagors) of the mortgages, ARMs behave more like fixed income securities and less like adjustable-rate securities and are subject to the risks associated with fixed income securities. In addition, during periods of rising interest rates, increases in the coupon rate of adjustable-rate mortgages generally lag current market interest rates slightly, thereby creating the potential for capital depreciation on such securities.

Stripped Mortgage-Backed Securities. SMBSs are derivative multi-class mortgage securities. SMBSs may be issued by agencies or instrumentalities of the U.S. Government, or by private originators of, or investors in, mortgage loans, including savings and loan associations, mortgage banks, commercial banks, investment banks and special purpose entities of the foregoing. SMBSs are usually structured with two classes that receive different proportions of the interest and principal distributions on a pool of mortgage assets. A common type of SMBS will have one class receiving some of the interest and most of the principal from the mortgage assets, while the other class will receive most of the interest and the remainder of the principal. In the most extreme case, one class will receive all of the interest (the IO class), while the other class will receive all of the principal (the principal-only or PO class). The yield to maturity on an IO class is extremely sensitive to the rate of principal payments (including prepayments) on the related underlying mortgage assets, and a rapid rate of principal payments may have a material adverse effect on the Fund’s yield to maturity from these securities. If the underlying mortgage assets experience greater than anticipated prepayments of principal, the Fund may fail to recoup some or all of its initial investment in these securities even if the security is in one of the highest rating categories.

Collateralized Bond Obligations, Collateralized Loan Obligations, and other Collateralized Debt Obligations. The Fund may invest in each of CBOs, CLOs, other CDOs and other similarly structured securities. CBOs, CLOs and CDOs are types of asset-backed securities. A CBO is a trust which is often backed by a diversified pool of high risk, below investment grade fixed income securities. The collateral

can be from many different types of fixed income securities such as high-yield debt, residential privately-issued mortgage-related securities, commercial privately-issued mortgage-related securities, trust preferred securities and emerging market debt. A CLO is a trust typically collateralized by a pool of loans, which may include, among others, domestic and foreign senior secured loans, senior unsecured loans and subordinate corporate loans, including loans that may be rated below investment grade or equivalent unrated loans. Other CDOs are trusts backed by other types of assets representing obligations of various parties. CBOs, CLOs and other CDOs may charge management fees and administrative expenses. For CBOs, CLOs and CDOs, the cash flows from the trust are split into two or more portions, called tranches, varying in risk and yield. The riskiest portion is the “equity” tranche which bears the bulk of defaults from the bonds or loans in the trust and serves to protect the other, more senior tranches from default in all but the most severe circumstances. Since they are partially protected from defaults, senior tranches from a CBO trust, CLO trust or trust of another CDO typically have higher ratings and lower yields than their underlying securities, and can be rated investment grade. Despite the protection from the equity tranche, CBO, CLO or other CDO tranches can experience substantial losses due to actual defaults, increased sensitivity to defaults due to collateral default and disappearance of protecting tranches, market anticipation of defaults, as well as aversion to CBO, CLO or other CDO securities as a class. The Fund may invest in any tranche, including the equity tranche, of a CBO, CLO or other CDO. The risks of an investment in a CBO, CLO or other CDO depend largely on the type of the collateral securities and the class of the instrument in which the Fund invests. Normally, CBOs, CLOs and other CDOs are privately offered and sold, and thus are not registered under the securities laws. As a result, investments in CBOs, CLOs and other CDOs may be characterized by the Fund as illiquid investments; however, an active dealer market may exist for CBOs, CLOs and other CDOs allowing them to qualify for Rule 144A under the Securities Act. In addition to the normal risks associated with debt instruments discussed elsewhere in this prospectus and in the Statement of Additional Information (e.g., prepayment risk, credit risk, liquidity risk, market risk, structural risk, legal risk, interest rate risk (which may be exacerbated if the interest rate payable on a structured financing changes based on multiples of changes in interest rates or inversely to changes in interest rates) and default risk), CBOs, CLOs and other CDOs carry additional risks including, but not limited to: (i) the possibility that distributions from collateral securities will not be adequate to make interest or other payments; (ii) the quality of the collateral may decline in value or default; (iii) the risk that the Fund may invest in CBOs, CLOs or other CDOs that are subordinate to other classes; and (iv) the complex structure of the security may not be fully understood at the time of investment and may produce disputes with the issuer or unexpected investment results.

Asset-Backed Securities. Asset-backed securities (“ABS”) are bonds backed by pools of loans or other receivables. ABS are created from many types of assets, including auto loans, credit card receivables, home equity loans and student loans. ABS are typically issued through special purpose vehicles that are bankruptcy remote from the issuer of the

Base Prospectus

collateral. The credit quality of an ABS transaction depends on the performance of the underlying assets. To protect ABS investors from the possibility that some borrowers could miss payments or even default on their loans, ABS include various forms of credit enhancement. Some ABS, particularly home equity loan ABS, are subject to interest rate risk and prepayment risk. A change in interest can affect the pace of payments on the underlying loans, which in turn affects total return on the securities. ABS also carry credit or default risk. If many borrowers on the underlying loans default, losses could exceed the credit enhancement level and result in losses to investors in an ABS. In addition, ABS have structural risk due to a unique characteristic known as early amortization, or early payout, risk. Built into the structure of most ABS are triggers for early payout, designed to protect investors from losses. These triggers are unique to each transaction and can include a big rise in defaults on the underlying loans, a sharp drop in the credit enhancement level or even the bankruptcy of the originator. Once early amortization begins, all incoming loan payments (after expenses are paid) are used to pay investors as quickly as possible based upon a predetermined priority of payment. The Fund may invest in any tranche, including the equity tranche, of ABS.

The Fund may invest in other types of asset-backed securities that are offered in the marketplace, including Enhanced Equipment Trust Certificates (“EETCs”). EETCs are typically issued by specially-created trusts established by airlines, railroads, or other transportation corporations. The proceeds of EETCs are used to purchase equipment, such as airplanes, railroad cars, or other equipment, which in turn serve as collateral for the related issue of the EETCs. The equipment generally is leased by the airline, railroad or other corporation, which makes rental payments to provide the projected cash flow for payments to EETC holders. Holders of EETCs must look to the collateral securing the certificates, typically together with a guarantee provided by the lessee corporation or its parent company for the payment of lease obligations, in the case of default in the payment of principal and interest on the EETCs. However, because principal and interest payments on EETCs are funded in the ordinary course by the lessee corporation, the Fund treats EETCs as corporate bonds/obligations for purposes of compliance testing and related classifications.

Mortgage-Related Derivative Instruments

The Fund may engage in derivative transactions related to mortgage-backed securities, including purchasing and selling exchange-listed and over-the-counter (“OTC”) put and call options, futures and forwards on mortgages and mortgage-backed securities. The Fund may also invest in mortgage-backed securities credit default swaps, which include swaps the reference obligation for which is a mortgage-backed security or related index, such as the CMBX Index (a tradeable index referencing a basket of commercial mortgage-backed securities), the TRX Index (a tradeable index referencing total return swaps based on commercial mortgage-backed securities) or the ABX (a tradeable index referencing a basket of sub-prime mortgage-backed securities). The Fund may invest in newly developed mortgage related derivatives that may hereafter become available.

Please see “Investment Objectives and Policies—Mortgage-Related and Other Asset-Backed Instruments” in the Statement of Additional Information and “Principal Risks of the Fund—Mortgage-Related and Asset-Backed Securities Risk” in this prospectus for additional information regarding the types of mortgage-related and other asset-backed instruments in which the Fund may invest and their related risks.

Municipal Bonds

Municipal bonds share the attributes of debt/fixed income securities in general, but are generally issued by states, municipalities and other political subdivisions, agencies, authorities and instrumentalities of states and multi-state agencies or authorities, and may be either taxable or tax-exempt instruments. The municipal bonds that the Fund may purchase include without limitation general obligation bonds and limited obligation bonds (or revenue bonds), including industrial development bonds issued pursuant to former federal tax law. General obligation bonds are obligations involving the credit of an issuer possessing taxing power and are payable from such issuer’s general revenues and not from any particular source. Limited obligation bonds are payable only from the revenues derived from a particular facility or class of facilities or, in some cases, from the proceeds of a special excise or other specific revenue source or annual revenues. Tax-exempt private activity bonds and industrial development bonds generally are also limited obligation bonds and thus are not payable from the issuer’s general revenues. The credit and quality of private activity bonds and industrial development bonds are usually related to the credit of the corporate user of the facilities. Payment of interest on and repayment of principal of such bonds is the responsibility of the corporate user (and/or any guarantor).

The Fund may invest in Build America Bonds, which are tax credit bonds created by the American Recovery and Reinvestment Act of 2009, which authorizes state and local governments to issue Build America Bonds as taxable bonds in 2009 and 2010, without volume limitations, to finance any capital expenditures for which such issuers could otherwise issue traditional tax-exempt bonds. State and local governments may receive a direct federal subsidy payment for a portion of their borrowing costs on Build America Bonds equal to 35% of the total coupon interest paid to investors (or 45% in the case of Recovery Zone Economic Development Bonds). The state or local government issuer can elect to either take the federal subsidy or pass the 35% tax credit along to bondholders. The Fund’s investments in Build America Bonds will result in taxable income and the Fund may elect to pass through to shareholders the corresponding tax credits. The tax credits can generally be used to offset federal income taxes and the alternative minimum tax, but such credits are generally not refundable. Build America Bonds involve similar risks as municipal bonds, including credit and market risk. They are intended to assist state and local governments in financing capital projects at lower borrowing costs and are likely to attract a broader group of investors than tax-exempt municipal bonds. For example, taxable funds, such as the Fund, may choose to invest in Build America Bonds. Although Build America Bonds were only authorized for issuance during 2009 and 2010, the program may have

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PIMCO Dynamic Income Fund

resulted in reduced issuance of tax-exempt municipal bonds during the same period. The Build America Bond program expired on December 31, 2010, at which point no further issuance of new Build America Bonds was permitted. As of the date of this prospectus, there is no indication that Congress will renew the program to permit issuance of new Build America Bonds.

The Fund may invest in pre-refunded municipal bonds. Pre-refunded municipal bonds are bonds that have been refunded to a call date prior to the final maturity of principal, or, in the case of pre-refunded municipal bonds commonly referred to as “escrowed-to-maturity bonds,” to the final maturity of principal, and remain outstanding in the municipal market. The payment of principal and interest of the pre-refunded municipal bonds held by the Fund is funded from securities in a designated escrow account that holds U.S. Treasury securities or other obligations of the U.S. Government (including its agencies and instrumentalities (“Agency Securities”)). Interest payments on pre-funded municipal bonds issued on or prior to December 31, 2017 are exempt from federal income tax; pre-funded municipal bonds issued after December 31, 2017 will not qualify for such tax-advantaged treatment. Pre-refunded municipal bonds usually will bear an AAA/Aaa rating (if a re-rating has been requested and paid for) because they are backed by U.S. Treasury securities or Agency Securities. Because the payment of principal and interest is generated from securities held in an escrow account established by the municipality and an independent escrow agent, the pledge of the municipality has been fulfilled and the original pledge of revenue by the municipality is no longer in place. The escrow account securities pledged to pay the principal and interest of the pre-refunded municipal bond do not guarantee the price movement of the bond before maturity. Issuers of municipal bonds refund in advance of maturity the outstanding higher cost debt and issue new, lower cost debt, placing the proceeds of the lower cost issuance into an escrow account to pre-refund the older, higher cost debt. Investment in pre-refunded municipal bonds held by the Fund may subject the Fund to interest rate risk and market risk. In addition, while a secondary market exists for pre-refunded municipal bonds, if the Fund sells pre-refunded municipal bonds prior to maturity, the price received may be more or less than the original cost, depending on market conditions at the time of sale.

The Fund may invest in municipal lease obligations. A lease is not a full faith and credit obligation of the issuer and is usually backed only by the borrowing government’s unsecured pledge to make annual appropriations for lease payments. There have been challenges to the legality of lease financing in numerous states, and, from time to time, certain municipalities have considered not appropriating money for lease payments. In deciding whether to purchase a lease obligation for the Fund, PIMCO will assess the financial condition of the borrower or obligor, the merits of the project, other credit characteristics of the obligor, the level of public support for the project and the legislative history of lease financing in the state. These securities may be less readily marketable than other municipal securities.

Some longer-term municipal bonds give the investor the right to “put” or sell the security at par (face value) within a specified number of days following the investor’s request—usually one to seven days. This demand feature enhances a security’s liquidity by shortening its effective maturity and enables it to trade at a price equal to or very close to par. If a demand feature terminates prior to being exercised, the Fund would hold the longer- term security, which could experience substantially more volatility.

The Fund may invest in municipal warrants, which are essentially call options on municipal bonds. In exchange for a premium, municipal warrants give the purchaser the right, but not the obligation, to purchase a municipal bond in the future. The Fund may purchase a warrant to lock in forward supply in an environment in which the current issuance of bonds is sharply reduced. Like options, warrants may expire worthless and may have reduced liquidity.

The Fund may invest in municipal bonds with credit enhancements such as letters of credit, municipal bond insurance and standby bond purchase agreements (“SBPAs”). Letters of credit are issued by a third party, usually a bank, to enhance liquidity and to ensure repayment of principal and any accrued interest if the underlying municipal bond should default. Municipal bond insurance, which is usually purchased by the bond issuer from a private, non-governmental insurance company, provides an unconditional and irrevocable guarantee that the insured bond’s principal and interest will be paid when due. Insurance does not guarantee the price of the bond. The credit rating of an insured bond reflects the credit rating of the insurer, based on its claims-paying ability. The obligation of a municipal bond insurance company to pay a claim extends over the life of each insured bond. Although defaults on insured municipal bonds have been low to date and municipal bond insurers have met their claims, there is no assurance that this will continue. A higher-than expected default rate could strain the insurer’s loss reserves and adversely affect its ability to pay claims to bondholders. Because a significant portion of insured municipal bonds that have been issued and are outstanding is insured by a small number of insurance companies, not all of which have the highest credit rating, an event involving one or more of these insurance companies, such as a credit rating downgrade, could have a significant adverse effect on the value of the municipal bonds insured by such insurance company or companies and on the municipal bond markets as a whole. An SBPA is a liquidity facility provided to pay the purchase price of bonds that cannot be re-marketed. The obligation of the liquidity provider (usually a bank) is only to advance funds to purchase tendered bonds that cannot be re-marketed and does not cover principal or interest under any other circumstances. The liquidity provider’s obligations under the SBPA are usually subject to numerous conditions, including the continued creditworthiness of the underlying borrower.

Loans and Other Indebtedness; Loan Participations and Assignments

The Fund may purchase indebtedness and participations in loans held and/or originated by private financial institutions, including commercial and residential mortgage loans, corporate loans and consumer loans, as well as interests and/or servicing or similar rights in such loans. Such

Base Prospectus

investments may be secured or unsecured and may be newly-originated (and may be specifically designed for the Fund). Indebtedness is different from traditional debt securities in that debt securities are part of a large issue of securities to the public whereas indebtedness may not be a security, and may represent a specific loan to a borrower. Loan participations typically represent direct participation, together with other parties, in a loan to a borrower, and generally are offered by banks or other financial institutions or lending syndicates. The Fund may participate in such syndications, or can buy part of a loan, becoming a part lender. When purchasing indebtedness and loan participations, the Fund assumes the credit risk associated with the borrower and may assume the credit risk associated with an interposed bank or other financial intermediary. The indebtedness and loan participations that the Fund may acquire may not be rated by any NRSRO.

A loan is often administered by an agent bank acting as agent for all holders. The agent bank administers the terms of the loan, as specified in the loan agreement. In addition, the agent bank is normally responsible for the collection of principal and interest payments from the borrower and the apportionment of these payments to the credit of all institutions which are parties to the loan agreement. Unless, under the terms of the loan or other indebtedness, the Fund has direct recourse against the borrower, the Fund may have to rely on the agent bank or other financial intermediary to apply appropriate credit remedies against a borrower.

A financial institution’s employment as agent bank might be terminated in the event that it fails to observe a requisite standard of care or becomes insolvent. A successor agent bank would generally be appointed to replace the terminated agent bank, and assets held by the agent bank under the loan agreement would likely remain available to holders of such indebtedness. However, if assets held by the agent bank for the benefit of the Fund were determined to be subject to the claims of the agent bank’s general creditors, the Fund might incur certain costs and delays in realizing payment on a loan or loan participation and could suffer a loss of principal and/or interest. In situations involving other interposed financial institutions (e.g., an insurance company or governmental agency) similar risks may arise.

Purchasers of loans and other forms of direct indebtedness depend primarily upon the creditworthiness of the borrower for payment of principal and interest. If the Fund does not receive scheduled interest or principal payments on such indebtedness, the NAV, market share price and/or yield of the Common Shares could be adversely affected. Loans that are fully secured offer the Fund more protection than an unsecured loan in the event of non-payment of scheduled interest or principal. However, there is no assurance that the liquidation of collateral from a secured loan would satisfy the borrower’s obligation, or that the collateral can be liquidated. In the event of the bankruptcy of a borrower, the Fund could experience delays or limitations in its ability to realize the benefits of any collateral securing a loan.

The Fund may acquire loans and loan participations with credit quality comparable to that of issuers of its securities investments. Indebtedness of companies whose creditworthiness is poor and/or subprime in quality involves substantially greater risks, and may be highly speculative. Some

companies may never pay off their indebtedness, or may pay only a small fraction of the amount owed. Consequently, when acquiring indebtedness of companies with poor credit, the Fund bears a substantial risk of losing the entire amount invested of the instrument acquired. The Fund may make purchases of indebtedness and loan participations to achieve income and/ or capital appreciation, rather than to seek income.

Loans and other types of direct indebtedness (which the Fund may purchase or otherwise gain exposure to) may not be readily marketable and may be subject to restrictions on resale. In connection with certain loan transactions, transaction costs that are borne by the Fund may include the expenses of third parties that are retained to assist with reviewing and conducting diligence, negotiating, structuring and servicing a loan transaction, and/or providing other services in connection therewith. Furthermore, the Fund may incur such costs in connection with loan transactions that are pursued by the Fund but not ultimately consummated (so-called “broken deal costs”). In some cases, negotiations involved in disposing of indebtedness may require weeks to complete. Consequently, some indebtedness may be difficult or impossible to dispose of readily at what PIMCO believes to be a fair price. In addition, valuation of illiquid indebtedness involves a greater degree of judgment in determining the Fund’s NAV than if that value were based on available market quotations, and could result in significant variations in the Fund’s daily share price. At the same time, some loan interests are traded among certain financial institutions and accordingly may be deemed liquid. As the market for different types of indebtedness develops, the liquidity of these instruments is expected to improve. Acquisitions of loan participations are considered to be debt obligations for purposes of the Fund’s investment restriction relating to the lending of funds or assets by the Fund.

Acquisition of loans through a purchase of a loan or direct assignment of a financial institution’s interests with respect to a loan may involve additional risks to the Fund. The purchaser of an assignment typically succeeds to all the rights and obligations under the loan agreement with the same rights and obligations as the assigning lender. Assignments may, however, be arranged through private negotiations between potential assignees and potential assignors, and the rights and obligations acquired by the purchaser of an assignment may differ from, and be more limited than, those held by the assigning lender. If a loan is foreclosed, the Fund could become part owner of any collateral, and would bear the costs and liabilities associated with owning and disposing of the collateral.

The Fund may make, participate in or acquire DIP financings. DIP financings are arranged when an entity seeks the protections of the bankruptcy court under Chapter 11 of the U.S. Bankruptcy Code. These financings allow the entity to continue its business operations while reorganizing under Chapter 11. Such financings constitute senior liens on unencumbered security (i.e., security not subject to other creditors’ claims). There is a risk that the entity will not emerge from Chapter 11 and be forced to liquidate its assets under Chapter 7 of the U.S. Bankruptcy Code. In the event of liquidation, the Fund’s only recourse will be against the property securing the DIP financing.The

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PIMCO Dynamic Income Fund

Fund may make investments in debt instruments and other securities or instruments directly or through one or more Subsidiaries. Each Subsidiary may invest, for example, in whole loans or in shares, certificates, notes or other securities representing the right to receive principal and interest payments due on fractions of whole loans or pools of whole loans or any other security or other instrument that the Fund may hold directly. The Fund will treat the assets of its Subsidiaries as assets of the Fund for purposes of determining compliance with various provisions of the 1940 Act applicable to the Fund, including those relating to investment policies (Section 8), capital structure and leverage (Section 18) and affiliated transactions and custody (Section 17).

Delayed Funding Loans and Revolving Credit Facilities

The Fund may enter into, or acquire participations in, delayed funding loans and revolving credit facilities, in which a bank or other lender agrees to make loans up to a maximum amount upon demand by the borrower during a specified term. These commitments may have the effect of requiring the Fund to increase its investment in a company at a time when it might not be desirable to do so (including at a time when the company’s financial condition makes it unlikely that such amounts will be repaid). Delayed funding loans and revolving credit facilities are subject to credit, interest rate and liquidity risk and the risks of being a lender.

Bonds

The Fund may invest in a wide variety of bonds of varying maturities issued by non-U.S. (foreign) and U.S. corporations and other business entities, governments and quasi-governmental entities and municipalities and other issuers. Bonds may include, among other things, fixed or variable/floating-rate debt obligations, including bills, notes, debentures, money market instruments and similar instruments and securities. Bonds generally are used by corporations as well as governments and other issuers to borrow money from investors. The issuer pays the investor a fixed or variable rate of interest and normally must repay the amount borrowed on or before maturity. Certain bonds are “perpetual” in that they have no maturity date.

Preferred Securities

Preferred securities represent an equity interest in a company that generally entitles the holder to receive, in preference to the holders of other stocks such as common stocks, dividends and a fixed share of the proceeds resulting from liquidation of the company. Unlike common stocks, preferred securities usually do not have voting rights. Preferred securities in some instances are convertible into common stock. Some preferred securities also entitle their holders to receive additional liquidation proceeds on the same basis as holders of a company’s common stock, and thus also represent an ownership interest in the company. Some preferred securities offer a fixed rate of return with no maturity date. Because they never mature, these preferred securities may act like long-term bonds, can be more volatile than other types of preferred securities and may have heightened sensitivity to changes in interest rates. Other preferred securities have a variable dividend, generally determined on a quarterly or other periodic basis, either

according to a formula based upon a specified premium or discount to the yield on particular U.S. Treasury securities or based on an auction process, involving bids submitted by holders and prospective purchasers of such securities. Although they are equity securities, preferred securities have certain characteristics of both debt securities and common stock. They are like debt securities in that their stated income is generally contractually fixed. They are like common stocks in that they do not have rights to precipitate bankruptcy proceedings or collection activities in the event of missed payments. Furthermore, preferred securities have many of the key characteristics of equity due to their subordinated position in an issuer’s capital structure and because their quality and value are heavily dependent on the profitability of the issuer rather than on any legal claims to specific assets or cash flows. Because preferred securities represent an equity ownership interest in a company, their value usually will react more strongly than bonds and other debt instruments to actual or perceived changes in a company’s financial condition or prospects, or to fluctuations in the equity markets.

In order to be payable, dividends on preferred securities must be declared by the issuer’s board of directors. In addition, distributions on preferred securities may be subject to deferral and thus may not be automatically payable. Income payments on some preferred securities are cumulative, causing dividends and distributions to accrue even if they are not declared by the board of directors of the issuer or otherwise made payable. Other preferred securities are non-cumulative, meaning that skipped dividends and distributions do not continue to accrue. There is no assurance that dividends on preferred securities in which the Fund invests will be declared or otherwise made payable.

Preferred securities have a liquidation value that generally equals their original purchase price at the date of issuance. The market values of preferred securities may be affected by favorable and unfavorable changes affecting the issuers’ industries or sectors. They also may be affected by actual and anticipated changes or ambiguities in the tax status of the security and by actual and anticipated changes or ambiguities in tax laws, such as changes in corporate and individual income tax rates or the rates applicable to dividends. The dividends paid on the preferred securities in which the Fund invests might not be eligible for the favorable tax treatment accorded to “qualified dividend income.” See “Taxation” in the Statement of Additional Information. Because the claim on an issuer’s earnings represented by preferred securities may become disproportionately large when interest rates fall below the rate payable on the securities or for other reasons, the issuer may redeem preferred securities, generally after an initial period of call protection in which the security is not redeemable. Thus, in declining interest rate environments in particular, the Fund’s holdings of higher dividend-paying preferred securities may be reduced and the Fund may be unable to acquire securities paying comparable rates with the redemption proceeds.

Convertible Securities and Synthetic Convertible Securities

Convertible securities (i.e., debt securities that may be converted at either a stated price or stated rate into underlying shares of common stock) have general characteristics similar to both debt securities and equity securities. Although to a lesser extent than with debt obligations,

Base Prospectus

the market value of convertible securities tends to decline as interest rates increase and, conversely, tends to increase as interest rates decline. In addition, because of the conversion feature, the market value of convertible securities tends to vary with fluctuations in the market value of the underlying common stocks and, therefore, also will react to variations in the general market for equity securities.

Convertible securities are investments that provide for a stable stream of income with generally higher yields than common stocks. There can be no assurance of current income because the issuers of the convertible securities may default on their obligations. Convertible securities, however, generally offer lower interest or dividend yields than non-convertible debt securities of similar credit quality because of the potential for equity-related capital appreciation. A convertible security, in addition to providing current income, offers the potential for capital appreciation through the conversion feature, which enables the holder to benefit from increases in the market price of the underlying common stock.

The Fund may invest in synthetic convertible securities, which are created through a combination of separate securities that possess the two principal characteristics of a traditional convertible security, that is, an income-producing component and the right to acquire a convertible component. The income-producing component is achieved by investing in non-convertible, income-producing securities such as bonds, preferred securities and money market instruments. The convertible component is achieved by purchasing warrants or options to buy common stock at a certain exercise price, or options on a stock index. The Fund may also purchase synthetic securities created by other parties, typically investment banks, including convertible structured notes. The income-producing and convertible components of a synthetic convertible security may be issued separately by different issuers and at different times. The values of synthetic convertible securities will respond differently to market fluctuations than a traditional convertible security because a synthetic convertible is composed of two or more separate securities or instruments, each with its own market value. Synthetic convertible securiti

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