SR-A Spire Inc

DESCRIPTION OF THE EQUITY UNITS

In this Description of the Equity Units, “Spire,” “we,” “us,” “our” and the “Company” refer only to Spire Inc. and any successor obligor, and not to any of its subsidiaries.

The following is a summary of some of the terms of the Equity Units. This summary, together with the summaries of the terms of the purchase contracts, the purchase contract and pledge agreement, our common stock and the notes set forth under the captions “Description of the Purchase Contracts,” “Certain Provisions of the Purchase Contract and Pledge Agreement” and “Description of the Notes” in this prospectus supplement and “Description of Capital Stock” in the accompanying prospectus, contain a description of the material terms of the Equity Units, but are only summaries and are not complete. This summary is subject to and is qualified by reference to all the provisions of the purchase contract and pledge agreement, the indenture (as defined under “Description of the Notes—Ranking”), the supplemental indenture (as defined under “Description of the Notes—Ranking”), the notes and the form of remarketing agreement, which has been attached as an exhibit to the purchase contract and pledge agreement, including the definitions of certain terms used therein, forms of which have been or will be filed and incorporated by reference as exhibits to the registration statement of which this prospectus supplement and the accompanying base prospectus form a part.

General

We will issue the Equity Units under the purchase contract and pledge agreement among us and U.S. Bank National Association (“U.S. Bank”), as purchase contract agent (the “purchase contract agent”), collateral agent (the “collateral agent”), custodial agent (the “custodial agent”) and securities intermediary. The Equity Units may be either Corporate Units or Treasury Units. The Equity Units will initially consist of 3,200,000 Corporate Units (or 3,500,000 Corporate Units if the underwriters exercise their option to purchase additional Equity Units in full), each with a stated amount of $50.

Each Corporate Unit offered will consist of:

either:

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“Applicable ownership interest” means, with respect to the Treasury portfolio,

If U.S. Treasury securities (or principal or interest strips thereof) that are to be included in the remarketing Treasury portfolio in connection with a successful optional remarketing have a yield that is less than zero, the remarketing Treasury portfolio will consist of an amount in cash equal to the aggregate principal amount at maturity of the U.S. Treasury securities described in clauses (1) and (2) under the first bullet above. If the provisions set forth in this paragraph apply, references to “Treasury security” and “U.S. Treasury securities (or principal or interest strips thereof)” in connection with the remarketing Treasury portfolio will, thereafter, be deemed to be references to such amount of cash.

So long as the Equity Units are in the form of Corporate Units, the related undivided beneficial ownership interest in the note or the applicable ownership interest in the Treasury portfolio described in clause (1) of the definition of “applicable ownership interest” with respect to, as applicable, the remarketing Treasury portfolio or the special event Treasury portfolio above (or $50 in cash, if the immediately preceding paragraph applies), as the case may be, will be pledged to us through the collateral agent to secure the holders’ obligations to purchase our common stock under the related purchase contracts.

Creating Treasury Units by Substituting a Treasury Security for a Note

Each holder of 20 Corporate Units may create, at any time other than after a successful remarketing or a special event redemption or during a blackout period (as defined below), 20 Treasury Units by substituting, for a note, a zero-coupon U.S. Treasury security (for example, CUSIP No. 912820L47) with a principal amount at maturity equal to $1,000 and maturing on or prior to March 1, 2024, which we refer to as a “Treasury security.” This substitution would create 20 Treasury Units and the note would be released from the pledge under the purchase contract and pledge agreement and delivered to the holder and would be tradable and transferable

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separately from the Treasury Units. Because Treasury securities and notes are issued in integral multiples of $1,000, holders of Corporate Units may make the substitution only in integral multiples of 20 Corporate Units. After a successful remarketing, holders may not create Treasury Units from Corporate Units or recreate Corporate Units from Treasury Units.

Each Treasury Unit will consist of:

The term “blackout period” means the period (1) if we elect to conduct an optional remarketing, from 4:00 p.m., New York City time, on the second business day (as defined below) immediately preceding the first day of the optional remarking period (as defined under “Description of the Purchase Contracts—Optional Remarketing” below) until the settlement date of such optional remarketing or the date we announce that such remarketing was unsuccessful and (2) after 4:00 p.m., New York City time, on the second business day immediately preceding the first day of the final remarketing period.

The term “business day” means any day that is not a Saturday or Sunday or a day on which banking institutions in The City of New York are authorized or required by law or executive order to close or a day on which the corporate trust office of the purchase contract agent is closed for business.

The Treasury Unit holder’s beneficial ownership interest in the Treasury security will be pledged to us through the collateral agent to secure the holder’s obligation to purchase our common stock under the related purchase contracts.

To create 20 Treasury Units, a holder is required to:

Upon receiving instructions from the purchase contract agent and receipt of the Treasury security, the collateral agent will release the related note from the pledge and deliver it to the purchase contract agent on behalf of the holder, free and clear of our security interest. The purchase contract agent then will:

The Treasury security will be substituted for the note and will be pledged to us through the collateral agent to secure the holder’s obligation to purchase shares of our common stock under the related purchase contracts. The note thereafter will trade and be transferable separately from the Treasury Units.

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Holders who create Treasury Units will be responsible for any taxes, governmental charges or other fees or expenses (including, without limitation, fees and expenses payable to the collateral agent) attributable to such collateral substitution. See “Certain Provisions of the Purchase Contract and Pledge Agreement—Miscellaneous.”

Recreating Corporate Units

Each holder of 20 Treasury Units will have the right, at any time, other than during a blackout period or after a successful remarketing or a special event redemption, to substitute for the related Treasury security held by the collateral agent a note having a principal amount equal to $1,000. This substitution would recreate 20 Corporate Units and the applicable Treasury security would be released from the pledge under the purchase contract and pledge agreement and delivered to the holder and would be tradable and transferable separately from the Corporate Units. Because Treasury securities and notes are issued in integral multiples of $1,000, holders of Treasury Units may make this substitution only in integral multiples of 20 Treasury Units. After a successful remarketing, holders may not recreate Corporate Units from Treasury Units.

To recreate 20 Corporate Units, a holder is required to:

Upon receiving instructions from the purchase contract agent and receipt of the note having a principal amount of $1,000, the collateral agent will promptly release the related Treasury security from the pledge and promptly instruct the securities intermediary to transfer such Treasury security to the purchase contract agent for distribution to the holder, free and clear of our security interest. The purchase contract agent then will:

The $1,000 principal amount note will be substituted for the Treasury security and will be pledged to us through the collateral agent to secure the holder’s obligation to purchase shares of our common stock under the related purchase contracts. The Treasury security thereafter will trade and be transferable separately from the Corporate Units.

Holders who recreate Corporate Units will be responsible for any taxes, governmental charges or other fees or expenses (including, without limitation, fees and expenses payable to the collateral agent) attributable to the collateral substitution. See “Certain Provisions of the Purchase Contract and Pledge Agreement—Miscellaneous.”

Payments on the Equity Units

Holders of Corporate Units and Treasury Units will receive quarterly contract adjustment payments payable by us at the rate of 6.75% per year on the stated amount of $50 per Equity Unit. We will make all contract adjustment payments on the Corporate Units and the Treasury Units quarterly in arrears on March 1, June 1, September 1 and December 1 of each year (except that if any such date is not a business day, contract

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adjustment payments will be payable on the following business day, without adjustment), commencing on June 1, 2021. Unless the purchase contracts have been terminated (as described under “Description of the Purchase Contracts—Termination” below), we will make such contract adjustment payments until the earliest of the purchase contract settlement date, the fundamental change early settlement date (in the case of a fundamental change early settlement, as described under “Description of the Purchase Contracts—Early Settlement Upon a Fundamental Change” below) and the most recent contract adjustment payment date on or before any other early settlement with respect to the related purchase contracts (in the case of an early settlement as described under “Description of the Purchase Contracts—Early Settlement” below). If the purchase contracts have been terminated, our obligation to pay the contract adjustment payments, including any accrued and unpaid contract adjustment payments and deferred contract adjustment payments (including compounded contract adjustment payments thereon), will cease. In addition, holders of Corporate Units will receive quarterly cash distributions consisting of their pro rata share of interest payments on the notes (or distributions on the applicable ownership interest in the Treasury portfolio, as applicable), equivalent to the rate of 0.75% per year. There will be no interest payments in respect of the Treasury securities that are a component of the Treasury Units, but to the extent that such holders of Treasury Units continue to hold the notes that were delivered to them when they created the Treasury Units, such holders will continue to receive the scheduled interest payments on their separate notes for as long as they hold the notes.

We have the right to defer payment of quarterly contract adjustment payments as described under “Description of the Purchase Contracts—Contract Adjustment Payments”.

Trading of the Equity Units

We do not intend to apply to list the Corporate Units on any securities exchange. Except in connection with early settlement, fundamental change early settlement, a termination event or settlement on the purchase contract settlement date with separate cash, unless and until substitution has been made as described in “—Creating Treasury Units by Substituting a Treasury Security for a Note” or “—Recreating Corporate Units,” neither the note or applicable ownership interest in the Treasury portfolio component of a Corporate Unit nor the Treasury security component of a Treasury Unit will trade separately from Corporate Units or Treasury Units. The note or applicable ownership interest in the Treasury portfolio component will trade as a unit with the purchase contract component of the Corporate Units, and the Treasury security component will trade as a unit with the purchase contract component of the Treasury Units. We have no obligation or current intention to apply for listing of the Corporate Units, the Treasury Units or the notes on any securities exchange. There can be no assurance as to the liquidity of any secondary market that may develop for the Corporate Units, the Treasury Units or the notes.

Ranking

The notes, which are included in the Equity Units, will be our unsecured and unsubordinated obligations and will rank on a parity in right of payment with all of our other unsecured and unsubordinated indebtedness from time to time outstanding. The notes will be issued under our indenture (defined under “Description of the Notes—Ranking”).

Our obligations with respect to contract adjustment payments will be subordinate in right of payment to our existing and future Priority Indebtedness, including the notes.

“Priority Indebtedness” means the principal, premium, interest and any other payment in respect of any of the following:

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However, “Priority Indebtedness” will not include trade accounts payable, accrued liabilities arising in the ordinary course of business, indebtedness to our subsidiaries, and any other indebtedness that effectively by its terms, or expressly provides that it, ranks junior to the notes or any of the foregoing.

The notes and our obligations with respect to contract adjustments payments will be structurally subordinated to existing or future preferred stock and indebtedness, guarantees and other liabilities, including trade payables, of our subsidiaries.

Our subsidiaries are separate and distinct legal entities from us. Our subsidiaries have no obligation to pay any amounts due on the notes or the purchase contracts or to provide us with funds to meet our respective payment obligations on the notes or purchase contracts. Any payment of dividends, loans or advances by our subsidiaries to us could be subject to statutory or contractual restrictions and will be contingent upon the subsidiaries’ earnings and business considerations. Our right to receive any assets of any of our subsidiaries upon their bankruptcy, liquidation or similar reorganization, and therefore the right of the holders of the notes or purchase contracts to participate in those assets, will be structurally subordinated to the claims of that subsidiary’s creditors, including trade creditors. Even if we are a creditor of any of our subsidiaries, our rights as a creditor would be subordinate to any security interest in the assets of our subsidiaries and any indebtedness of our subsidiaries senior to that held by us. As of December 31, 2020, our subsidiaries had approximately $1,954.6 million of outstanding debt to external sources (including securities due within one year), which would be structurally senior to the notes.

Voting and Certain Other Rights

Prior to the delivery of shares of common stock under each purchase contract, such purchase contract shall not entitle the holder of the Corporate Units or Treasury Units to any rights of a holder of shares of our common stock, including, without limitation, the right to vote or receive any dividends or other payments or distributions or to consent to or to receive notice as a shareholder or other rights in respect of our common stock.

Agreed U.S. Federal Income Tax Treatment

Each beneficial owner of an Equity Unit, by purchasing a Corporate Unit, will be deemed to have agreed (unless otherwise required by any taxing authority) (1) to be treated as the owner of each of the purchase contract, the related note and the applicable ownership interests in the Treasury portfolio or Treasury security, as the case may be, for U.S. federal, state and local income tax purposes, (2) to treat the note as indebtedness for all U.S. federal, state and local tax purposes, and (3) to allocate, as of the issue date, 100% of the purchase price paid for the Corporate Units to its ownership interest in the notes and 0% to each purchase contract, which will establish its initial tax basis in each purchase contract as $0 and the beneficial owner’s initial tax basis in the note as $50. This position will be binding on each beneficial owner of each Equity Unit, but not on the IRS. See “Material United States Federal Income Tax Consequences.”

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Repurchase of the Equity Units

We may purchase from time to time any of the Equity Units that are then outstanding by tender, in the open market, by private agreement or otherwise, subject to compliance with applicable law.

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DESCRIPTION OF THE PURCHASE CONTRACTS

In this Description of the Purchase Contracts, “Spire,” “we,” “us,” “our” and the “Company” refer only to Spire Inc. and any successor obligor, and not to any of its subsidiaries.

The following is a summary of some of the terms of the purchase contracts. The purchase contracts will be issued pursuant to the purchase contract and pledge agreement among us, the purchase contract agent, the collateral agent, the custodial agent and the securities intermediary. The summaries of the purchase contracts and the purchase contract and pledge agreement contain a description of the material terms of the contracts but are only summaries and are not complete. This summary is subject to and is qualified by reference to all the provisions of the purchase contract and pledge agreement, the indenture (as defined under “Description of the Notes—Ranking”), the supplemental indenture (as defined under “Description of the Notes—Ranking”), the notes and the form of remarketing agreement, including the definitions of certain terms used therein, forms of which have been or will be filed and incorporated by reference as an exhibit to the registration statement of which this prospectus supplement and the accompanying base prospectus form a part.

Purchase of Common Stock

Each purchase contract that is a component of a Corporate Unit or a Treasury Unit will obligate its holder to purchase, and us to issue and deliver, on March 1, 2024 (or if such day is not a business day, the following business day) (the “purchase contract settlement date”), for $50 in cash a number of shares of our common stock equal to the settlement rate (together with cash, if applicable, in lieu of any fractional shares of common stock in the manner described below), in each case, unless the purchase contract terminates prior to that date or is settled early at the holder’s option. The number of shares of our common stock issuable upon settlement of each purchase contract on the purchase contract settlement date (which we refer to as the “settlement rate”) will be determined as follows, subject to adjustment as described under “—Anti-dilution Adjustments” below:

Accordingly, if the applicable market value of our common stock is greater than the threshold appreciation price, the aggregate market value of the shares of common stock issued upon settlement of each purchase contract will be higher than the stated amount, assuming that the market price of the common stock on the purchase contract settlement date is the same as the applicable market value of the common stock. If the applicable market value is the same as the threshold appreciation price, the aggregate market value of the shares issued upon settlement will be equal to the stated amount, assuming that the market price of the common stock on the purchase contract settlement date is the same as the applicable market value of the common stock.

Accordingly, if the applicable market value of our common stock is less than the threshold appreciation price, but greater than the reference price, the aggregate market value of the shares of common stock issued upon settlement of each purchase contract will be equal to the stated amount, assuming that the market price of the common stock on the purchase contract settlement date is the same as the applicable market value of the common stock.

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Accordingly, if the applicable market value of our common stock is less than the reference price, the aggregate market value of the shares of common stock issued upon settlement of each purchase contract will be less than the stated amount, assuming that the market price on the purchase contract settlement date is the same as the applicable market value of the common stock. If the market price of the common stock is the same as the reference price, the aggregate market value of the shares will be equal to the stated amount, assuming that the market price of the common stock on the purchase contract settlement date is the same as the applicable market value of the common stock.

The threshold appreciation price is equal to $50 divided by the minimum settlement rate (such quotient rounded to the nearest $0.0001), which is $78.6906 and represents appreciation of approximately 22.5% over the reference price.

If you elect to settle your purchase contract early in the manner described under “—Early Settlement,” the number of shares of our common stock issuable upon settlement of such purchase contract will be the minimum settlement rate, subject to adjustment as described under “—Anti-dilution Adjustments.” If you elect to settle your purchase contract early upon a fundamental change, the number of shares of our common stock issuable upon settlement will be determined as described under “—Early Settlement Upon a Fundamental Change.” We refer to the minimum settlement rate and the maximum settlement rate as the “fixed settlement rates.”

The “applicable market value” means, as determined by us, the average volume-weighted average price, or VWAP, of our common stock on each trading day during the 20 consecutive trading day period beginning on and including the 21st scheduled trading day immediately preceding the purchase contract settlement date (such 20 consecutive trading day period, the “market value averaging period”). The “VWAP” of our common stock means, for the relevant trading day, the per share VWAP on the principal exchange or quotation system on which our common stock is listed or admitted for trading as displayed under the heading Bloomberg VWAP on Bloomberg page SR <EQUITY> AQR (or its equivalent successor if that page is not available) in respect of the period from the scheduled open of trading on the relevant trading day until the scheduled close of trading on the relevant trading day (or if such VWAP is unavailable, the market price of one share of our common stock on such trading day determined, using a volume-weighted average method, by a nationally recognized independent investment banking firm retained for this purpose by us).

A “trading day” means, for purposes of determining a VWAP or closing price, a day (i) on which the principal exchange or quotation system on which our common stock is listed or admitted for trading is scheduled to be open for business and (ii) on which there has not occurred or does not exist a market disruption event.

A “market disruption event” means any of the following events:

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If a market disruption event occurs on any scheduled trading day during the market value averaging period, we will notify investors on the calendar day on which such event occurs.

If 20 trading days for our common stock have not occurred during the period from, and including, the first day of the market value averaging period to, and including, the second scheduled trading day immediately prior to the purchase contract settlement date, all remaining trading days in the market value averaging period will be deemed to occur on that second scheduled trading day immediately prior to the purchase contract settlement date, and the daily VWAP of our common stock for each of those remaining trading days will be the daily VWAP of our common stock on that second scheduled trading day or, if such day is not a trading day, the closing price as of such day.

The “closing price” per share of our common stock means, on any date of determination, the closing sale price or, if no closing sale price is reported, the last reported sale price of our common stock on the principal U.S. securities exchange on which our common stock is listed, or if our common stock is not so listed on a U.S. securities exchange, the average of the last quoted bid and ask prices for our common stock in the over-the-counter market as reported by OTC Markets Group Inc. or similar organization, or, if those bid and ask prices are not available, the market value of our common stock on that date as determined by a nationally recognized independent investment banking firm retained by us for this purpose.

We will not issue any fractional shares of our common stock upon settlement of a purchase contract. Instead of a fractional share, the holder will receive an amount of cash equal to the percentage of a whole share represented by such fractional share multiplied by the closing price of our common stock on the trading day immediately preceding the purchase contract settlement date (or the trading day immediately preceding the relevant settlement date, in the case of early settlement). If, however, a holder surrenders for settlement at one time more than one purchase contract, then the number of shares of our common stock issuable pursuant to such purchase contracts will be computed based upon the aggregate number of purchase contracts surrendered.

Unless:

then, on the purchase contract settlement date,

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The common stock will then be issued and delivered to the holder or the holder’s designee on the purchase contract settlement date. We will pay all stock transfer and similar taxes attributable to the initial issuance and delivery of the shares of our common stock pursuant to the purchase contracts, unless any such tax is due because the holder requests such shares to be issued in a name other than such holder’s name.

Prior to the settlement of a purchase contract, the shares of our common stock underlying each purchase contract will not be outstanding, and the holder of the purchase contract will not have any voting rights, rights to dividends or other distributions or other rights of a holder of our common stock by virtue of holding such purchase contract.

By purchasing a Corporate Unit or a Treasury Unit, a holder will be deemed to have, among other things:

Remarketing

Unless we have previously redeemed the notes in a special event redemption, we have agreed to enter into a remarketing agreement with one or more remarketing agents, the “remarketing agent,” no later than 20 days prior to the first day of the final remarketing period or, if we elect to conduct an optional remarketing, no later than 20 days prior to the first day of the optional remarketing period.

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During a blackout period that relates to each remarketing period:

We refer to each of an “optional remarketing” and a “final remarketing” as a “remarketing.” In a remarketing, the notes that are a part of Corporate Units (except, in the case of a final remarketing, where the holder has elected to settle the purchase contract through payment of separate cash) and any separate notes whose holders have elected to participate in the remarketing, as described under “Description of the Notes—Remarketing of Notes That Are Not Included in Corporate Units,” will be remarketed.

Following any successful remarketing of the notes:

All such modifications will take effect only if the remarketing is successful, without the consent of holders, on the optional remarketing settlement date or the purchase contract settlement date, as the case may be, and will apply to all notes, whether or not included in the remarketing. All other terms of the notes will remain unchanged.

In order to remarket the notes, we, in consultation with the remarketing agent, may reset the interest rate on the notes (either upward or downward) in order to produce the required price in the remarketing, as discussed under “—Optional Remarketing” and “—Final Remarketing” below.

We will use commercially reasonable efforts to ensure that, if required by applicable law, a registration statement, including a prospectus, with regard to the full amount of the notes to be remarketed will be effective under the securities laws in a form that may be used by the remarketing agent in connection with the remarketing (unless a registration statement is not required under the applicable laws and regulations that are in effect at that time or unless we conduct any remarketing in accordance with an exemption under the securities laws).

We will separately pay a fee to the remarketing agent for its services as remarketing agent. Holders whose notes are remarketed will not be responsible for the payment of any remarketing fee in connection with the remarketing.

Optional Remarketing

Unless a termination event or a special event redemption has occurred, we may elect, at our option, to engage the remarketing agent pursuant to the terms of the remarketing agreement, to remarket the notes over a period selected by us that begins on or after November 29, 2023 (the second business day immediately preceding the last interest payment date prior to the purchase contract settlement date) and ends any time on or before February 13, 2024 (the 9^th calendar day immediately preceding the first day of the final remarketing period) (which we call the “optional remarketing window”). Any remarketing in the optional remarketing window will occur during a five-business day remarketing period (which we refer to as an “optional remarketing period”) consisting of five sequential possible remarketing dates selected by us. We refer to a remarketing that occurs during the optional remarketing period as an “optional remarketing” and the date the notes are priced in an

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optional remarketing as the “optional remarketing date.” In any optional remarketing, the aggregate principal amount of the notes that are a part of Corporate Units and any separate notes whose holders have elected to participate in the optional remarketing, as described under “Description of the Notes—Remarketing of Notes That Are Not Included in Corporate Units,” will be remarketed. If we elect to conduct an optional remarketing, the remarketing agent will use its commercially reasonable efforts to obtain a price for the notes that results in proceeds of at least 100% of the aggregate of the remarketing Treasury portfolio purchase price (as defined below) and the separate notes purchase price (as defined below). To obtain that price, we may, in consultation with the remarketing agent, reset the interest rate, as described under “Description of the Notes—Interest Rate Reset.” We will request that the depository notify its participants holding Corporate Units, Treasury Units and separate notes of our election to conduct an optional remarketing no later than 15 calendar days prior to the date we begin the optional remarketing.

An optional remarketing on any remarketing date will be considered successful if the remarketing agent is able to remarket the notes for a price of at least 100% of the remarketing Treasury portfolio purchase price and the separate notes purchase price.

Following a successful optional remarketing of the notes, on the optional remarketing settlement date (as defined below), the portion of the remarketing proceeds equal to the remarketing Treasury portfolio purchase price will, except as described below, be used to purchase the remarketing Treasury portfolio and the remaining proceeds attributable to the notes underlying the Corporate Units will be remitted to the purchase contract agent for distribution pro rata to the holders of such Corporate Units. The portion of the proceeds attributable to the separate notes sold in the remarketing will be remitted to the custodial agent for distribution on the optional remarketing settlement date pro rata to the holders of such separate notes.

If we elect to conduct an optional remarketing and the remarketing is successful:

If we do not elect to conduct an optional remarketing during the optional remarketing period or no optional remarketing succeeds for any reason, the notes will continue to be a component of the Corporate Units or will continue to be held separately and the remarketing agent will use its commercially reasonable efforts to remarket the notes during the final remarketing period.

For the purposes of a successful optional remarketing, “remarketing Treasury portfolio purchase price” means the lowest aggregate ask-side price quoted by a primary U.S. government securities dealer in New York City to the quotation agent selected by us between 9:00 a.m. and 4:00 p.m., New York City time, on the optional

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remarketing date for the purchase of the remarketing Treasury portfolio for settlement on the optional remarketing settlement date; provided that if the Treasury portfolio consists of cash, “remarketing Treasury portfolio purchase price” means the amount of such cash.

Following a successful optional remarketing and receipt of the proceeds, the collateral agent will purchase, at the remarketing Treasury portfolio purchase price, a Treasury portfolio, which we refer to as the “remarketing Treasury portfolio”, consisting of:

If U.S. Treasury securities (or principal or interest strips thereof) that are to be included in the remarketing Treasury portfolio in connection with a successful optional remarketing have a yield that is less than zero, the remarketing Treasury portfolio will consist of an amount in cash equal to the aggregate principal amount at maturity of the U.S. Treasury securities described in the bullet points above. If the provisions set forth in this paragraph apply, references in this prospectus supplement to a “Treasury security” and “U.S. Treasury securities (or principal or interest strips thereof)” in connection with the remarketing Treasury portfolio will, thereafter, be deemed to be references to such amount in cash.

The applicable ownership interests in the remarketing Treasury portfolio will be substituted for the undivided beneficial ownership interests in notes that are components of the Corporate Units and the portion of the remarketing Treasury portfolio described in the first clause above will be pledged to us through the collateral agent to secure the Corporate Unit holders’ obligation under the purchase contracts. On the purchase contract settlement date, for each Corporate Unit, $50 of the proceeds from the remarketing Treasury portfolio will automatically be applied to satisfy the Corporate Unit holder’s obligation to purchase common stock under the purchase contract. In addition, proceeds from the portion of the remarketing Treasury portfolio described in the second bullet, which will equal the interest payment (assuming no reset of the interest rate) that would have been paid on the notes that were components of the Corporate Units at the time of remarketing, will be paid on the purchase contract settlement date to the holders of the Corporate Units.

If we elect to remarket the notes during the optional remarketing window and a successful remarketing has not occurred on or prior to the last day of the relevant optional remarketing period, we will cause a notice of the failed remarketing to be published no later than 9:00 a.m., New York City time, on the business day immediately following the last date of the optional remarketing period. This notice will be validly published by making a timely release to any appropriate news agency, including Bloomberg Business News and the Dow Jones News Service. We will similarly cause a notice of a successful remarketing of the notes to be published no later than 9:00 a.m., New York City time, on the business day immediately following the date of such successful remarketing.

On each business day during any optional remarketing period, we have the right in our sole and absolute discretion to determine whether or not an optional remarketing will be attempted. At any time and from time to time during the optional remarketing period prior to the announcement of a successful optional remarketing, we have the right to postpone any optional remarketing in our sole and absolute discretion.

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Final Remarketing

Unless a termination event, a successful optional remarketing or a special event redemption has previously occurred, we will remarket the notes during the five business day period ending on, and including, February 28, 2024 (the second business day immediately preceding the purchase contract settlement date). We refer to this period as the “final remarketing period,” the remarketing during this period as the “final remarketing” and the date the notes are priced in the final marketing as the “final remarketing date.” In the final remarketing, the aggregate principal amount of the notes that are a part of Corporate Units (except where the holder has elected to settle the purchase contract through payment of separate cash) and any separate notes whose holders have elected to participate in the final remarketing will be remarketed. The remarketing agent will use its commercially reasonable efforts to obtain a price for the notes to be remarketed that results in proceeds of at least 100% of the principal amount of all the notes offered in the remarketing. To obtain that price, we may, in consultation with the remarketing agent, reset the interest rate on the notes as described under “Description of the Notes—Interest Rate Reset.” We will request that the depository notify its participants holding Corporate Units, Treasury Units and separate notes of the final remarketing no later than 15 calendar days prior to the first day of the final remarketing period. In such notice, we will set forth the dates of the final remarketing period, applicable procedures for holders of separate notes to participate in the final remarketing, the applicable procedures for holders of Corporate Units to create Treasury Units and for holders of Treasury Units to recreate Corporate Units, the applicable procedures for holders of Corporate Units to settle their purchase contracts early and any other applicable procedures, including the procedures that must be followed by a holder of separate notes in the case of a failed remarketing if a holder of separate notes wishes to exercise its right to put its notes to us as described below and under “Description of the Notes—Put Option upon Failed Remarketing.” We have the right to postpone the final remarketing in our sole and absolute discretion on any day prior to the last three business days of the final remarketing period.

A remarketing during the final remarketing period will be considered successful if the remarketing agent is able to remarket the notes for a price of at least 100% of the aggregate principal amount of all the notes offered in the remarketing.

If the final remarketing is successful:

Unless a termination event has occurred, a holder has effected an early settlement or a fundamental change early settlement, there has been a successful optional remarketing, or a special event redemption has occurred, each Corporate Unit holder has the option at any time on or after the date we give notice of a final remarketing to notify the purchase contract agent at any time prior to 4:00 p.m., New York City time, on the second business day immediately prior to the first day of the final remarketing period of its intention to settle the related purchase contracts on the purchase contract settlement date with separate cash and to provide that cash on or prior to the

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business day immediately prior to the first day of the final remarketing period, as described under “—Notice to Settle with Cash.” The notes of any holder of Corporate Units who has not given this notice or failed to deliver the cash will be remarketed during the final remarketing period. In addition, holders of notes that do not underlie Corporate Units may elect to participate in the remarketing as described under “Description of the Notes—Remarketing of Notes That Are Not Included in Corporate Units.”

If, in spite of using its commercially reasonable efforts, the remarketing agent cannot remarket the notes during the final remarketing period at a price equal to or greater than 100% of the aggregate principal amount of the notes offered in the remarketing, a condition precedent set forth in the remarketing agreement has not been fulfilled or a successful remarketing has not occurred for any other reason, in each case resulting in a “failed remarketing,” holders of all notes will have the right to put their notes to us for an amount equal to the principal amount of their notes (the “put price”), plus accrued and unpaid interest, if any. The conditions precedent in the remarketing agreement will include, but not be limited to, the timely filing with the SEC of all material related to the remarketing required to be filed by us, the truth and correctness of certain representations and warranties made by us in the remarketing agreement, the furnishing of certain officer’s certificates to the remarketing agent, and the receipt by the remarketing agent of customary “comfort letters” from our auditors and opinions of counsel. A holder of Corporate Units will be deemed to have automatically exercised this put right with respect to the notes underlying such Corporate Units unless the holder has provided a written notice to the purchase contract agent of its intention to settle the purchase contract with separate cash as described below under “—Notice to Settle with Cash” prior to 4:00 p.m., New York City time, on the second business day immediately prior to the purchase contract settlement date, and on or prior to the business day immediately preceding the purchase contract settlement date has delivered the $50 in cash per purchase contract. Settlement with separate cash may only be effected in integral multiples of 20 Corporate Units. If a holder of Corporate Units elects to settle with separate cash, upon receipt of the required cash payment, the related notes underlying the Corporate Units will be released from the pledge under the purchase contract and pledge agreement and delivered promptly to the purchase contract agent for delivery to the holder. The holder of the Corporate Units will then receive the applicable number of shares of our common stock on the purchase contract settlement date. The cash received by the collateral agent upon this settlement with separate cash may be invested in permitted investments, as defined in the purchase contract and pledge agreement, and the portion of the proceeds equal to the aggregate purchase price of all purchase contracts of such holders will be paid to us on the purchase contract settlement date. Any excess funds received by the collateral agent in respect of any such permitted investments over the aggregate purchase price remitted to us in satisfaction of the obligations of the holders under the purchase contracts will be distributed to the purchase contract agent for ratable payment to the applicable holders who settled with separate cash. Unless a holder of Corporate Units has elected to settle the related purchase contracts with separate cash and delivered the separate cash on or prior to the business day immediately preceding the purchase contract settlement date, the holder will be deemed to have elected to apply the put price against the holder’s obligations to pay the aggregate purchase price for the shares of our common stock to be issued under the related purchase contracts, thereby satisfying the obligations in full, and we will deliver to the holder our common stock pursuant to the related purchase contracts.

If a successful final remarketing has not occurred on or prior to February 28, 2024 (the last day of the final remarketing period), we will cause a notice of the failed remarketing of the notes to be published no later than 9:00 a.m., New York City time, on the business day immediately following the last date of the final remarketing period. This notice will be validly published by making a timely release to any appropriate news agency, including Bloomberg Business News and the Dow Jones News Service.

Early Settlement

Subject to the conditions described below, a holder of Corporate Units or Treasury Units may settle the related purchase contracts at any time prior to 4:00 p.m., New York City time, on the second business day immediately preceding the purchase contract settlement date, other than during a blackout period in the case of Corporate Units. An early settlement may be made only in integral multiples of 20 Corporate Units or 20

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Treasury Units; however, if the Treasury portfolio has replaced the notes as a component of the Corporate Units following a successful optional remarketing or a special event redemption, holders of Corporate Units may settle early only in such integral multiples of Corporate Units as may be determined us or, in the case of a remarketing, by the remarketing agent upon a successful remarketing of the notes. In order to settle purchase contracts early, a holder of Equity Units must deliver to the purchase contract agent at the corporate trust office of the purchase contract agent or its agent, in each case, in the continental United States of America, (1) a completed “Election to Settle Early” form, along with the Corporate Unit or Treasury Unit certificate, if they are in certificated form and (2) a cash payment in immediately available funds in an amount equal to:

So long as you hold Equity Units as a beneficial interest in a global security certificate deposited with the depository, procedures for early settlement will also be governed by applicable depository procedures and standing arrangements between the depository and the purchase contract agent.

The early settlement right is also subject to the condition that, if required under U.S. federal securities laws, we have a registration statement under the Securities Act in effect with respect to the shares of common stock and other securities, if any, deliverable upon settlement of a purchase contract. We have agreed that, if such a registration statement is required, we will use our commercially reasonable efforts to (1) have a registration statement in effect covering those shares of common stock and other securities, if any, to be delivered in respect of the purchase contracts being settled and (2) provide a prospectus in connection therewith, in each case in a form that may be used in connection with the early settlement right (it being understood that if there is a material business transaction or development that has not yet been publicly disclosed, we will not be required to file such registration statement or provide such a prospectus, and the early settlement right will not be available, until we have publicly disclosed such transaction or development; provided that we will use commercially reasonable efforts to make such disclosure as soon as it is commercially reasonable to do so). In the event that a holder seeks to exercise its early settlement right and a registration statement is required to be effective in connection with the exercise of such right but no such registration statement is then effective, the holder’s exercise of such right will be void unless and until such a registration statement is effective.

Upon early settlement, except as described below in “—Early Settlement Upon a Fundamental Change,” we will sell, and the holder will be entitled to buy, the minimum settlement rate of shares of our common stock (or in the case of an early settlement following a reorganization event, such number of exchange property units, as described under “—Reorganization Events” below) for each purchase contract being settled (regardless of the market price of our common stock on the date of early settlement), subject to adjustment under the circumstances described under “—Anti-dilution Adjustments” below. We will cause, on the second business day after the applicable early settlement date, (1) the shares of our common stock to be issued and (2) the related notes or applicable ownership interests in the Treasury portfolio or Treasury securities, as the case may be, underlying the Equity Units and securing such purchase contracts to be released from the pledge under the purchase contract and pledge agreement, and delivered to the purchase contract agent for delivery to the holder. Upon early settlement, the holder will be entitled to receive any accrued and unpaid contract adjustment payments (including any accrued and unpaid deferred contract adjustment payments and compounded contract adjustment payments thereon) to, but excluding, the contract adjustment payment date immediately preceding the early settlement date. The holder’s right to receive future contract adjustment payments will also terminate.

If the purchase contract agent receives a completed “Election to Settle Early” form (along with the Corporate Unit or Treasury Unit certificate, if they are in certificated form) and payment of $50 for each

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purchase contract being settled (and, if required, an amount equal to the contract adjustment payments payable on the next contract adjustment payment date) prior to 4:00 p.m., New York City time, on any business day and all conditions to early settlement have been satisfied, then that day will be considered the early settlement date. If the purchase contract agent receives the foregoing at or after 4:00 p.m., New York City time, on any business day or at any time on a day that is not a business day, then the next business day will be considered the early settlement date.

Early Settlement Upon a Fundamental Change

If a “fundamental change” (as defined below) occurs prior to the 20th business day preceding the purchase contract settlement date, then, following the fundamental change, each holder of a purchase contract, subject to certain conditions described in this prospectus supplement, will have the right to accelerate and settle the purchase contract early on the fundamental change early settlement date (defined below) at the settlement rate determined as if the applicable market value equaled the stock price (as defined below), plus an additional make-whole amount of shares (such additional make-whole amount of shares being hereafter referred to as the “make-whole shares”). We refer to this right as the “fundamental change early settlement right.”

We will provide each of the holders and the purchase contract agent with a notice of the completion of a fundamental change within 10 business days after the effective date of a fundamental change. The notice will specify (1) a date (subject to postponement as described below, the “fundamental change early settlement date”), which will be at least 10 days after the date of the notice but no later than the earlier of 20 days after the date of such notice and one business day prior to the purchase contract settlement date, on which date we will deliver shares of our common stock to holders who exercise the fundamental change early settlement right, (2) the date by which holders must exercise the fundamental change early settlement right, (3) the applicable settlement rate and number of make-whole shares, (4) the amount and kind (per share of common stock) of the cash, securities and other consideration receivable by the holder upon settlement and (5) the amount of accrued and unpaid contract adjustment payments (including any deferred contract adjustment payments and compounded contract adjustment payments thereon), if any, that will be paid upon settlement to holders exercising the fundamental change early settlement right. To exercise the fundamental change early settlement right, you must deliver to the purchase contract agent at the corporate trust office of the purchase contract agent or its agent, in each case, in the continental United States of America, during the period beginning on the date we deliver notice that a fundamental change has occurred and ending at 4:00 p.m., New York City time, on the second business day immediately preceding the fundamental change early settlement date (such period, subject to extension as described below, the “fundamental change exercise period”), the certificate evidencing your Corporate Units or Treasury Units if they are held in certificated form, and payment of $50 for each purchase contract being settled in immediately available funds.

A “fundamental change” will be deemed to have occurred if any of the following occurs:

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If you exercise the fundamental change early settlement right, we will deliver to you on the fundamental change early settlement date for each purchase contract with respect to which you have elected fundamental change early settlement, a number of shares (or exchange property units, if applicable) equal to the settlement rate described above plus the additional make-whole shares. In addition, on the fundamental change early settlement date, we will pay you the amount of any accrued and unpaid contract adjustment payments (including any deferred contract adjustment payments and compounded contract adjustment payments thereon) to, but excluding, the fundamental change early settlement date, unless the date on which the fundamental change early settlement right is exercised occurs following any record date and prior to the related scheduled contract adjustment payment date, and we are not deferring the related contract adjustment payment, in which case we will instead pay all accrued and unpaid contract adjustment payments to the holder as of such record date. You will also receive on the fundamental change early settlement date the notes or the applicable ownership interest in the Treasury portfolio or Treasury securities underlying the Corporate Units or Treasury Units, as the case may be, with respect to which you are effecting a fundamental change early settlement, which, in each case, shall have been released from the pledge under the purchase contract and pledge agreement. If you do not elect to exercise your fundamental change early settlement right, your Corporate Units or Treasury Units will remain outstanding and will be subject to normal settlement on the purchase contract settlement date.

We have agreed that, if required under the U.S. federal securities laws, we will use our commercially reasonable efforts to (1) have in effect throughout the fundamental change exercise period a registration statement covering the common stock and other securities, if any, to be delivered in respect of the purchase contracts being settled and (2) provide a prospectus in connection therewith, in each case in a form that may be used in connection with the fundamental change early settlement (it being understood that for so long as there is a material business transaction or development that has not yet been publicly disclosed (but in no event for a period longer than 90 days), we will not be required to file such registration statement or provide such a prospectus, and the fundamental change early settlement right will not be available, until we have publicly disclosed such transaction or development; provided that we will use commercially reasonable efforts to make such disclosure as soon as it is commercially reasonable to do so). In the event that a holder seeks to exercise its fundamental change early settlement right and a registration statement is required to be effective in connection with the exercise of such right but no such registration statement is then effective or a blackout period is continuing, the holder’s exercise of such right will be void unless and until such a registration statement is effective and no blackout period is continuing. The fundamental change exercise period will be extended by the number of days during such period on which no such registration statement is effective or a blackout period is continuing (provided that the fundamental change exercise period will not be extended beyond the fourth business day preceding the purchase contract settlement date) and the fundamental change early settlement date will be postponed to the third business day following the end of the fundamental change exercise period. If, but for the proviso contained in the immediately preceding sentence, the fundamental change early settlement date would occur on or after the purchase contract settlement date, we will deliver to any holder of purchase contracts on the purchase contract settlement date the applicable number of make-whole shares in addition to a number of shares equal to the settlement rate, determined as if the applicable market value were equal to the relevant stock price.

Unless the Treasury portfolio has replaced the notes as a component of the Corporate Units as result of a successful remarketing or a special event redemption, holders of Corporate Units may exercise the fundamental change early settlement right only in integral multiples of 20 Corporate Units. If the Treasury portfolio has replaced the notes as a component of Corporate Units, holders of the Corporate Units may exercise the fundamental change early settlement right only in integral multiples of such number of Corporate Units as may be determined by us or, in the case of a remarketing, the remarketing agent upon a successful remarketing of the notes.

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A holder of Treasury Units may exercise the fundamental change early settlement right only in integral multiples of 20 Treasury Units.

Calculation of Make-Whole Shares. The number of make-whole shares per purchase contract applicable to a fundamental change early settlement will be calculated by us and will be determined by reference to the table below, based on the date on which the fundamental change occurs or becomes effective (the “effective date”) and the “stock price” in the fundamental change, which will be:

The stock prices set forth in the second row of the table (i.e., the column headers) will be adjusted upon the occurrence of certain events requiring anti-dilution adjustments to the fixed settlement rates in a manner inversely proportional to the adjustments to the fixed settlement rates.

Each of the make-whole share amounts in the table will be subject to adjustment in the same manner and at the same time as the fixed settlement rates as set forth under “—Anti-dilution Adjustments.”

The exact stock price and effective date applicable to a fundamental change may not be set forth on the table, in which case:

Notice to Settle with Cash

Unless a termination event has occurred, a holder effects an early settlement or a fundamental change early settlement with respect to the underlying purchase contract, a successful remarketing has occurred, or a special event redemption has occurred, a holder of Corporate Units may settle the related purchase contract with separate cash by delivering the Corporate Unit certificate, if in certificated form, to the purchase contract agent at the corporate trust office of the purchase contract agent or its agent, in each case, in the continental United States of

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America, with the completed “Notice to Settle with Cash” form at any time on or after the date we give notice of a final remarketing and prior to 4:00 p.m., New York City time on the business day immediately preceding the first day of the final remarketing period or, if there has been a failed final remarketing, on the second business day immediately preceding the purchase contract settlement date. Holders of Corporate Units may only cash-settle Corporate Units in integral multiples of 20 Corporate Units.

The holder must also deliver to the securities intermediary the required cash payment in immediately available funds. Such payment must be delivered prior to 4:00 p.m., New York City time, on the first business day immediately preceding the final remarketing period or, if there has been a failed remarketing, on the first business day immediately preceding the purchase contract settlement date.

Upon receipt of the cash payment, the related note will be released from the pledge arrangement and transferred to the purchase contract agent for distribution to the holder of the related Corporate Units. The holder of the Corporate Units will then receive the applicable number of shares of our common stock on the purchase contract settlement date.

If a holder of Corporate Units that has given notice of its election to settle with cash fails to deliver the cash by the applicable time and date specified above, such holder shall be deemed to have consented to the disposition of its notes in the final remarketing, or to have exercised its put right (as described under “—Final Remarketing” above), in each case, as applicable.

Any cash received by the collateral agent upon cash settlement may, upon our written direction, be invested in permitted investments, as defined in the purchase contract and pledge agreement, and the portion of the proceeds equal to the aggregate purchase price of all purchase contracts of such holders will be paid to us on the purchase contract settlement date. Any excess funds received by the collateral agent in respect of permitted investments over the aggregate purchase price remitted to us in satisfaction of the obligations of the holders under the purchase contracts will be distributed to the purchase contract agent for payment to the holders who settled with cash.

Contract Adjustment Payments

Contract adjustment payments in respect of Corporate Units and Treasury Units will be fixed at a rate per year of 6.75% of the stated amount of $50 per purchase contract. Contract adjustment payments payable for any period will be computed on the basis of a 360-day year of twelve 30-day months. Contract adjustment payments will accrue from the date of issuance of the purchase contracts and will be payable quarterly in arrears on March 1, June 1, September 1 and December 1, commencing on June 1, 2021.

Contract adjustment payments will be payable to the holders of purchase contracts as they appear on the books and records of the purchase contract agent at the close of business on the relevant record dates, which will be the 15th day of the month immediately preceding the month in which the relevant payment date falls (whether or not a business day). These distributions will be paid through the purchase contract agent, which will hold amounts received in respect of the contract adjustment payments for the benefit of the holders of the purchase contracts relating to the Equity Units. Subject to any applicable laws and regulations, each such payment will be made as described under “Certain Provisions of the Purchase Contract and Pledge Agreement—Book-Entry System.”

If any date on which contract adjustment payments are to be made on the purchase contracts related to the Corporate Units or Treasury Units is not a business day, then payment of the contract adjustment payments payable on that date will be made on the next succeeding day that is a business day, and no interest or payment will be paid in respect of the delay.

For the avoidance of doubt, subject to our right to defer contract adjustment payments, all record holders of purchase contracts on any record date will be entitled to receive the full contract adjustment payment due on the

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related contract adjustment payment date regardless of whether the holder of such purchase contract elects to settle such purchase contract early (whether at its option or in connection with a fundamental change) following such record date.

Our obligations with respect to contract adjustment payments will be subordinated and junior in right of payment to our obligations under any of our Priority Indebtedness, including the notes.

We may, at our option and upon prior written notice of at least one business day before the record date to the purchase contract agent and the holders, defer all or part of the contract adjustment payments, but not beyond the purchase contract settlement date (or, with respect to an early settlement upon a fundamental change, not beyond the fundamental change early settlement date or, with respect to an early settlement other than upon a fundamental change, not beyond the contract adjustment payment date immediately preceding the early settlement date).

Deferred contract adjustment payments will accrue additional contract adjustment payments at the rate equal to 7.50% per annum (which is equal to the rate of total distributions on the Corporate Units), compounded on each contract adjustment payment date, to, but excluding, the contract adjustment payment date on which such deferred contract adjustment payments are paid. We refer to additional contract adjustment payments that accrue on deferred contract adjustment payments as “compounded contract adjustment payments.” We may pay any such deferred contract adjustment payments (including compounded contract adjustment payments thereon) on any scheduled contract adjustment payment date; provided that in order to pay deferred contract adjustment payments on any scheduled contract adjustment payment date other than the purchase contract settlement date, we must deliver written notice thereof to holders of the Equity Units and the purchase contract agent on or before the relevant record date. If the purchase contracts are terminated (upon the occurrence of certain events of bankruptcy, insolvency or similar reorganization with respect to us), the right to receive contract adjustment payments and deferred contract adjustment payments (including compounded contract adjustment payments thereon) will also terminate.

If we exercise our option to defer the payment of contract adjustment payments, then, until the deferred contract adjustment payments (including compounded contract adjustment payments thereon) have been paid, we will not (1) declare or pay any dividends on, or make any distributions on, or redeem, purchase or acquire, or make a liquidation payment with respect to, any shares of our capital stock, (2) make any payment of principal of, or interest or premium, if any, on, or repay, repurchase or redeem any of our debt securities that rank on parity with, or junior to, the contract adjustment payments, or (3) make any guarantee payments under any guarantee by us of securities of any of our subsidiaries if our guarantee ranks on parity with, or junior to, the contract adjustment payments.

The restrictions listed above do not apply to:

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Anti-dilution Adjustments

Each fixed settlement rate will be subject to the following adjustments:

(1) If we issue common stock as a dividend or distribution on our common stock to all or substantially all holders of our common stock, or if we effect a share split or share combination, the fixed settlement rates will be adjusted based on the following formula:

Any adjustment made pursuant to this paragraph (1) shall become effective as of the close of business on (x) the record date for such dividend or other distribution or (y) the effective date for such share split or share combination becomes effective, as applicable. If any dividend or distribution in this paragraph (1) is declared but not so paid or made, the new fixed settlement rates shall be readjusted, on the date that our board of directors determines not to pay or make such dividend or distribution, to the fixed settlement rates that would then be in effect if such dividend or distribution had not been declared.

(2)    If we distribute to all holders of our common stock any rights, options or warrants entitling them for a period of not more than 45 calendar days after the date of distribution thereof to subscribe for or purchase our

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common stock, in any case at an exercise price per share of our common stock less than the closing price of our common stock on the business day immediately preceding the date of the time of announcement of such issuance, the fixed settlement rates will be increased based on the following formula:

SR₁ = SR₀ x [(OS₀ + X) / (OS₀ + Y)]

where,

If any right, option or warrant described in this paragraph (2) is not exercised or converted prior to the expiration of the exercisability or convertibility thereof (and as a result no additional shares of common stock are delivered or issued pursuant to such rights or warrants), the new fixed settlement rates shall be readjusted, as of the date of such expiration, to the fixed settlement rates that would then be in effect had the increase with respect to the issuance of such rights, options or warrants been made on the basis of delivery or issuance of only the number of shares of common stock actually delivered.

For purposes of this paragraph (2), in determining whether any rights, options or warrants entitle the holders to subscribe for or purchase shares of the common stock at a price per share of our common stock less than the closing price of our common stock on the business day immediately preceding the time of announcement of such issuance, and in determining the aggregate price payable to exercise such rights, options or warrants, there shall be taken into account any consideration received by us for such rights, options or warrants and any amount payable on exercise or conversion thereof, the value of such consideration, if other than cash, to be determined in good faith by our board of directors. Any increase made under this paragraph (2) will be made successively whenever any such rights, options or warrants are issued and shall become effective immediately after the close of business on the record date for such distribution.

(3)    (a) If we distribute shares of capital stock, evidences of indebtedness or other assets or property of us to all holders of our common stock (excluding (i) any dividend, distribution, rights, warrants or options as to which an adjustment was effected pursuant to clause (1) or (2) above, (ii) any dividend or distribution paid exclusively in cash, and (iii) any spin-off to which the provisions in clause 3(b) below apply), the fixed settlement rates will be increased based on the following formula:

SR₁ = SR₀ x [SP₀ / (SP₀ – FMV)]

where,

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Notwithstanding the foregoing, if “FMV” (as defined above) exceeds “SP₀” (as defined above), in lieu of the foregoing increase, each holder of a purchase contract shall receive, for each purchase contract, at the same time and upon the same terms as holders of shares of our common stock, the amount of such distributed shares of capital stock, evidences of indebtedness or other assets or property that such holder would have received if such holder owned a number of shares of our common stock equal to the maximum settlement rate on the record date for such dividend or distribution.

(b)    However, if we distribute to all holders of our common stock, capital stock of any class or series, or similar equity interest, of or relating to a subsidiary or other business unit, in each case that will be listed on a U.S. national securities exchange which we refer to as a “spin-off”, then the fixed settlement rates will instead be increased based on the following formula:

The adjustment to the fixed settlement rates under this paragraph 3(b) will occur on the last day of the valuation period; provided that if a holder elects to early settle the purchase contracts, or the purchase contract settlement date occurs, in either case, during the valuation period, references with respect to 10 trading days shall be deemed replaced with such lesser number of trading days as have elapsed between the ex-dividend date of such spin-off and the date on which such holder elected its early settlement right, or the business day immediately preceding the purchase contract settlement date, as the case may be, in determining the fixed settlement rates.

If any dividend or distribution described in this paragraph (3) is declared but not so paid or made, the new fixed settlement rates shall be readjusted, as of the date our board of directors determines not to pay or make such dividend or distribution, to the fixed settlement rates that would then be in effect if such dividend or distribution had not been declared.

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(4)    If any regular, quarterly cash dividend or distribution is made to all or substantially all holders of our common stock during any quarterly fiscal period exceeds $0.65 per share (the “reference dividend”), the fixed settlement rates will be increased based on the following formula:

SR₁ = SR₀ x [(SP₀ – T) / (SP₀ – C)]

where,

Notwithstanding the foregoing, if “C” (as defined above) exceeds “SP₀” (as defined above), in lieu of the foregoing increase, each holder of a purchase contract shall receive, for each purchase contract, at the same time and upon the same terms as holders of shares of our common stock, the amount of distributed cash that such holder would have received if such holder owned a number of shares of our common stock equal to the maximum settlement rate on the record date for such cash dividend or distribution.

The reference dividend will be subject to an inversely proportional adjustment whenever each fixed settlement rate is adjusted, other than pursuant to this paragraph (4). For the avoidance of doubt, the reference dividend will be zero in the case of a cash dividend that is not a regular quarterly dividend.

If any dividend or distribution described in this paragraph (4) is declared but not so paid or made, the new fixed settlement rates shall be readjusted, as of the date our board of directors determines not to pay or make such dividend or distribution, to the fixed settlement rates that would then be in effect if such dividend or distribution had not been declared.

(5)    If we or any of our subsidiaries makes a payment in respect of a tender offer or exchange offer for our common stock to the extent that the cash and value of any other consideration included in the payment per share of our common stock validly tendered or exchanged exceeds the closing price of a share of our common stock on the trading day next succeeding the last date on which tenders or exchanges may be made pursuant to such tender or exchange offer, the fixed settlement rates will be increased based on the following formula:

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The adjustment to the fixed settlement rates under the preceding paragraph (5) will occur at the close of business on the trading day on which such tender or exchange offer expires.

The term “ex-dividend date,” when used with respect to any issuance or distribution on our common stock or any other security, means the first date on which our common stock or such other security, as applicable, trades, regular way, on the principal U.S. securities exchange or quotation system on which our common stock or such other security, as applicable, is listed or quoted at that time, without the right to receive the issuance or distribution.

We currently do not have a shareholders rights plan with respect to our common stock. To the extent that we have a shareholders rights plan involving the issuance of share purchase rights or other similar rights to all or substantially all holders of our common stock in effect upon settlement of a purchase contract, you will receive, in addition to the common stock issuable upon settlement of any purchase contract, the related rights for the common stock under the shareholders rights plan, unless, prior to any settlement of a purchase contract, the rights have separated from the common stock, in which case each fixed settlement rate will be adjusted at the time of separation as if we made a distribution to all holders of our common stock as described in clause (3) above, subject to readjustment in the event of the expiration, termination or redemption of the rights under the shareholder rights plan.

For United States federal income tax purposes, you may be treated as receiving a constructive distribution from us with respect to the purchase contract if (1) a fixed settlement rate is adjusted (or fails to be adjusted) and, as a result of the adjustment (or failure to adjust), your proportionate interest in our assets or earnings and profits is increased, and (2) the adjustment (or failure to adjust) is not made pursuant to a bona fide, reasonable anti-dilution formula. For example, if a fixed settlement rate is adjusted as a result of a distribution that is taxable to the holders of our common stock, such as a cash dividend, you will be deemed to have received a “constructive distribution” of our stock. Thus, under certain circumstances, an adjustment to a fixed settlement rate might give rise to a taxable dividend to you even though you will not receive any cash in connection with such adjustment. In addition, Non-U.S. Holders (as defined in “Material United States Federal Income Tax Consequences”) may, in certain circumstances, be deemed to have received a distribution subject to United States federal withholding tax. See “Material United States Federal Income Tax Consequences—U.S. Holders—Purchase Contracts—Adjustment to Settlement Rate” and “Material United States Federal Income Tax Consequences—Non-U.S. Holders—United States Federal Withholding Tax.”

In addition, we may increase the fixed settlement rates if our board of directors deems it advisable to avoid or diminish any income tax to holders of our common stock resulting from any dividend or distribution of shares (or rights to acquire shares) or from any event treated as a dividend or distribution for income tax purposes or for any other reasons.

Adjustments to the fixed settlement rates will be calculated to the nearest 1/10,000th of a share. No adjustment to the fixed settlement rates will be required unless the adjustment would require an increase or decrease of at least one percent in the fixed settlement rates. If any adjustment is not required to be made because

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it would not change the fixed settlement rates by at least one percent, then the adjustment will be carried forward and taken into account in any subsequent adjustment. All adjustments will be made not later than the purchase contract settlement date, any early settlement date, any fundamental change early settlement date and the time at which we are required to determine the relevant settlement rate or amount of make-whole shares (if applicable) in connection with any settlement with respect to the purchase contracts.

No adjustment to the fixed settlement rates will be made if holders of Equity Units participate, as a result of holding the Equity Units and without having to settle the purchase contracts that form part of the Equity Units, in the transaction that would otherwise give rise to an adjustment as if they held a number of shares of our common stock equal to the maximum settlement rate, at the same time and upon the same terms as the holders of common stock participate in the transaction.

Except as described above, the fixed settlement rates will not be adjusted:

We will, as promptly as practicable after the fixed settlement rates are adjusted, provide written notice of the adjustment to the holders of Equity Units.

If an adjustment is made to the fixed settlement rates, an adjustment also will be made to the reference price and the threshold appreciation price on an inversely proportional basis solely to determine which of the clauses of the definition of settlement rate will be applicable to determine the settlement rate with respect to the purchase contract settlement date or any fundamental change early settlement date.

If any adjustment to the fixed settlement rates becomes effective, or any effective date, expiration time, ex-date or record date for any stock split or reverse stock split, tender or exchange offer, issuance, dividend or distribution (relating to a required fixed settlement rate adjustment) occurs, during the period beginning on, and including, (i) the open of business on a first trading day of the market value averaging period or (ii) in the case of the optional early settlement or fundamental change early settlement, the relevant early settlement date or the fundamental change early settlement date and, in each case, ending on, and including, the date on which we deliver shares of our common stock under the related purchase contract, we will make appropriate adjustments to the fixed settlement rates and/or the number of shares of our common stock deliverable upon settlement with respect to the purchase contract, in each case, consistent with the methodology used to determine the anti-dilution adjustments set forth above. If any adjustment to the fixed settlement rates becomes effective, or any effective date, expiration time, ex-date or record date for any stock split or reverse stock split, tender or exchange offer, issuance, dividend or distribution (relating to a required fixed settlement rate adjustment) occurs, during the period used to determine the “stock price” or any other averaging period hereunder, we will make appropriate adjustments to the applicable prices, consistent with the methodology used to determine the anti-dilution adjustments set forth above.

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Reorganization Events

The following events are defined as “reorganization events”:

Following the effective date of a reorganization event, the settlement rate shall be determined by reference to the value of an exchange property unit, and we shall deliver, upon settlement of any purchase contract, a number of exchange property units equal to the number of shares of our common stock that we would otherwise be required to deliver. An “exchange property unit” is the kind and amount of common stock, other securities, other property or assets (including cash or any combination thereof) receivable in such reorganization event (without any interest thereon, and without any right to dividends or distribution thereon which have a record date that is prior to the applicable settlement date) per share of our common stock by a holder of common stock that is not a person with which we are consolidated or into which we are merged or which merged into us or to which such sale or transfer was made, as the case may be (we refer to any such person as a “constituent person”), or an affiliate of a constituent person, to the extent such reorganization event provides for different treatment of common stock held by the constituent person and/or the affiliates of the constituent person, on the one hand, and non-affiliates of a constituent person, on the other hand. In the event holders of our common stock (other than any constituent person or affiliate thereof) have the opportunity to elect the form of consideration to be received in such transaction, the exchange property unit that holders of the Corporate Units or Treasury Units are entitled to receive will be deemed to be the weighted average of the types and amounts of consideration actually received by the holders of our common stock.

In the event of such a reorganization event, the person formed by such consolidation or merger or the person which acquires our assets shall execute and deliver to the purchase contract agent an agreement providing that the holder of each Equity Unit that remains outstanding after the reorganization event (if any) shall have the rights described in the preceding paragraph. Such supplemental agreement shall provide for adjustments to the amount of any securities constituting all or a portion of an exchange property unit and/or adjustments to the fixed settlement rates, which, for events subsequent to the effective date of such reorganization event, shall be as nearly equivalent as may be practicable to the adjustments provided for under “—Anti-dilution Adjustments” above. The provisions described in the preceding two paragraphs shall similarly apply to successive reorganization events.

In connection with any reorganization event, we will also adjust the reference dividend based on the number of shares of common stock comprising an exchange property unit and (if applicable) the value of any non-stock consideration comprising an exchange property unit. If an exchange property unit is composed solely of non-stock consideration, the reference dividend will be zero.

Termination

The purchase contract and pledge agreement provides that the purchase contracts and the obligations and rights of us and of the holders of Corporate Units and Treasury Units thereunder (including the holders’

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obligation and right to purchase and receive shares of our common stock and to receive accrued and unpaid contract adjustment payments, including deferred contract adjustment payments and compounded contract adjustment payments thereon) will immediately and automatically terminate upon the occurrence of a termination event (as defined below).

Upon any termination event, the Equity Units will represent the right to receive the notes underlying the undivided beneficial interest in the notes, applicable ownership interests in the Treasury Portfolio, or the Treasury securities, as the case may be, forming part of such Equity Units. Upon the occurrence of a termination event, we will promptly give the purchase contract agent, the collateral agent and the holders written notice of such termination event and the collateral agent will release the related interests in the notes, applicable ownership interests in the Treasury portfolio or Treasury securities, as the case may be, from the pledge arrangement and transfer such interests in the notes, applicable ownership interests in the Treasury portfolio or Treasury securities to the purchase contract agent for distribution to the holders of Corporate Units and Treasury Units. If a holder is entitled to receive notes in an aggregate principal amount that is not an integral multiple of $1,000, we will issue upon request of the purchase contract agent notes in denominations of $50 and integral multiples thereof in exchange for notes in denominations of $1,000 or integral multiples thereof. In addition, if any holder is entitled to receive, with respect to its applicable ownership interests in the Treasury portfolio or its pledged Treasury securities, any securities having a principal amount at maturity of less than $1,000, the purchase contract agent will dispose of such securities for cash and pay the cash received to the holder in lieu of such applicable ownership in the Treasury portfolio or such Treasury securities. Upon any termination event, however, such release and distribution may be subject to a delay. In the event that the Company becomes the subject of a case under the U.S. Bankruptcy Code, such delay may occur as a result of the automatic stay under the U.S. Bankruptcy Code and continue until such automatic stay has been lifted. Moreover, claims arising out of the notes will be subject to the equitable jurisdiction and powers of the bankruptcy court.

A “termination event” means any of the following events with respect to the Company:

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Pledged Securities and Pledge

The undivided beneficial ownership interests in the notes, or, following a successful optional remarketing or a special event redemption, the applicable ownership interests in the Treasury portfolio (as described under the first clause of the definition of “remarketing Treasury portfolio” or “special event Treasury portfolio”, as the case may be), that are a component of the Corporate Units or, if substituted, the beneficial ownership interest in the Treasury securities that are a component of the Treasury Units, collectively, the “pledged securities,” will be pledged to the collateral agent for our benefit pursuant to the purchase contract and pledge agreement to secure your obligation to purchase shares of our common stock under the related purchase contracts. The rights of the holders of the Corporate Units and Treasury Units with respect to the pledged securities will be subject to our security interest therein. No holder of Corporate Units or Treasury Units will be permitted to withdraw the pledged securities related to such Corporate Units or Treasury Units from the pledge arrangement except:

Subject to our security interest and the terms of the purchase contract and pledge agreement, each holder of a Corporate Unit (unless the Treasury portfolio has replaced the notes as a component of the Corporate Unit), will be entitled through the purchase contract agent and the collateral agent to all of the proportional rights and preferences of the related notes (including distribution, voting, redemption, repayment and liquidation rights). Each holder of Treasury Units and each holder of Corporate Units (if the Treasury portfolio has replaced the notes as a component of the Corporate Units), will retain beneficial ownership of the related Treasury securities or the applicable ownership interests in the Treasury portfolio, as applicable, pledged in respect of the related purchase contracts. We will have no interest in the pledged securities other than our security interest.

Except as described in “Certain Provisions of the Purchase Contract and Pledge Agreement—General,” upon receipt of distributions on the pledged securities, the collateral agent will distribute such payments to the purchase contract agent, which in turn will distribute those payments to the holders in whose names the Corporate Units or Treasury Units are registered at the close of business on the record date for the distribution.

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CERTAIN PROVISIONS OF THE PURCHASE CONTRACT AND PLEDGE AGREEMENT

In this Description of the Purchase Contract and Pledge Agreement, “Spire,” “we,” “us,” “our” and the “Company” refer only to Spire Inc. and any successor obligor, and not to any of its subsidiaries.

The following is a summary of some of the other terms of the purchase contract and pledge agreement. The summary contains a description of additional material terms of the agreement but is only a summary and is not complete. This summary is subject to and is qualified by reference to all the provisions of the purchase contract and pledge agreement, including the definitions of certain terms used therein, the form of which has been or will be filed and incorporated by reference as an exhibit to the registration statement of which this prospectus supplement and the accompanying base prospectus form a part.

General

Except as described under “—Book-Entry System” below, payments on the Corporate Units and Treasury Units will be payable, the purchase contracts will be settled, and transfers of the Corporate Units and Treasury Units will be registrable at, the office of the purchase contract agent or its agent, in each case, in the continental United States of America. In addition, if the Corporate Units or Treasury Units do not remain in book-entry form, we will make payments on the Corporate Units and Treasury Units by check mailed to the address of the person entitled thereto as shown on the security register or, if the holder timely so requests, by a wire transfer to the account designated by the holder by a prior written notice.

Shares of common stock will be delivered on the purchase contract settlement date (or earlier upon early settlement), or, if the purchase contracts have terminated, the related pledged securities will be delivered (subject to delays, including potentially as a result of the imposition of the automatic stay under the U.S. Bankruptcy Code, as described under “Description of the Purchase Contracts—Termination”) at the corporate trust office of the purchase contract agent or its agent upon presentation and surrender of the applicable Corporate Unit or Treasury Unit certificate, if in certificated form.

If Corporate Units or Treasury Units are in certificated form and the holder fails to present and surrender the certificate evidencing the Corporate Units or Treasury Units to the purchase contract agent on or prior to the purchase contract settlement date, the shares of common stock issuable upon settlement with respect to the related purchase contract will be registered in the name of the purchase contract agent or its nominee. The shares, together with any distributions, will be held by the purchase contract agent as agent for the benefit of the holder until the certificate is presented and surrendered or the holder provides satisfactory evidence that the certificate has been destroyed, lost or stolen, together with any indemnity that may be required by the purchase contract agent and us.

If the purchase contracts terminate prior to the purchase contract settlement date, the related pledged securities are transferred to the purchase contract agent for distribution to the holders, and a holder fails to present and surrender the certificate evidencing the holder’s Corporate Units or Treasury Units, if in certificated form, to the purchase contract agent, the related pledged securities delivered to the purchase contract agent and payments on the pledged securities will be held by the purchase contract agent as agent for the benefit of the holder until the applicable certificate is presented, if in certificated form, or the holder provides the evidence and indemnity described above.

No service charge will be made for any registration of transfer or exchange of the Corporate Units or Treasury Units, except for any tax or other governmental charge that may be imposed in connection therewith.

The purchase contract agent will have no obligation to invest or to pay interest on any amounts it holds pending payment to any holder.

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Modification

The purchase contract and pledge agreement will contain provisions permitting us, the purchase contract agent and the collateral agent, to modify the purchase contract and pledge agreement without the consent of the holders for any of the following purposes:

The purchase contract and pledge agreement will contain provisions allowing us, the purchase contract agent and the collateral agent, subject to certain limited exceptions, to modify the terms of the purchase contracts or the purchase contract and pledge agreement with the consent of the holders of not less than a majority of the outstanding Equity Units, with holders of Corporate Units and Treasury Units voting as a single class. However, no such modification may, without the consent of the holder of each outstanding purchase contract affected thereby:

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However, if any amendment or proposal would adversely affect only the Corporate Units or only the Treasury Units, then only the affected class of holders will be entitled to vote on such amendment or proposal, and such amendment or proposal will not be effective except with the consent of the holders of not less than a majority of such class or, if referred to in the seven bullets above, each holder affected thereby.

No Consent to Assumption

Each holder of a Corporate Unit or a Treasury Unit will be deemed under the terms of the purchase contract and pledge agreement, by the purchase of such Corporate Unit or Treasury Unit, to have expressly withheld any consent to the assumption under Section 365 of the U.S. Bankruptcy Code or otherwise, of the related purchase contracts by us, our receiver, liquidator or trustee or person or entity performing similar functions in the event that we become a debtor under the U.S. Bankruptcy Code or other similar state or federal law providing for reorganization or liquidation.

Consolidation, Merger and Conveyance of Assets as an Entirety

We will agree not to merge or consolidate with any other person or sell or convey all or substantially all of our assets to any person unless (i) either we are the continuing entity, or the successor entity (if other than us) is a corporation organized and existing under the laws of the United States of America or a State thereof or the District of Columbia and such corporation expressly assumes all of our responsibilities and liabilities under the purchase contracts, the Corporate Units, the Treasury Units, the purchase contract and pledge agreement, the remarketing agreement (if any) and the indenture by one or more supplemental agreements in form satisfactory to the purchase contract agent, the collateral agent and the indenture trustee, executed and delivered to the purchase contract agent, the collateral agent and the indenture trustee by such corporation, and (ii) we or such successor corporation, as the case may be, will not, immediately after such merger or consolidation, or such sale or conveyance, be in default in the performance of any of its obligations or covenants under such agreements.

In case of any such consolidation, merger, sale or conveyance, and upon any such assumption by the successor corporation, such successor corporation shall succeed to and be substituted for us, with the same effect as if it had been named in the purchase contracts, the Corporate Units, the Treasury Units, the purchase contract and pledge agreement and the remarketing agreement (if any) as us and (other than in the case of a lease) we shall be relieved of any further obligation under the purchase contracts, the Corporate Units, the Treasury Units, the purchase contract and pledge agreement and the remarketing agreement (if any).

Title

We, the purchase contract agent and the collateral agent may treat the registered owner of any Corporate Units or Treasury Units as the absolute owner of the Corporate Units or Treasury Units for the purpose of making payment (subject to the record date provisions described above), settling the related purchase contracts and for all other purposes.

Replacement of Equity Unit Certificates

In the event that physical certificates have been issued, any mutilated Corporate Unit or Treasury Unit certificate will be replaced by us at the expense of the holder upon surrender of the certificate to the purchase contract agent at the corporate trust office of the purchase contract agent or its agent, in each case, in the continental United States of America. Corporate Unit or Treasury Unit certificates that become destroyed, lost or stolen will be replaced by us at the expense of the holder upon delivery to us and the purchase contract agent of evidence of their destruction, loss or theft satisfactory to us and the purchase contract agent. In the case of a destroyed, lost or stolen Corporate Unit or Treasury Unit certificate, an indemnity satisfactory to the purchase contract agent and us may be required at the expense of the holder before a replacement certificate will be issued.

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Notwithstanding the foregoing, we will not be obligated to issue any Corporate Unit or Treasury Unit certificates on or after the business day immediately preceding the purchase contract settlement date or the date on which the purchase contracts have terminated. The purchase contract and pledge agreement will provide that, in lieu of the delivery of a replacement Corporate Unit or Treasury Unit certificate, the purchase contract agent, upon delivery of the evidence and indemnity described above, will, in the case of the purchase contract settlement date, deliver the shares of common stock issuable pursuant to the purchase contracts included in the Corporate Units or Treasury Units evidenced by the certificate, or, if the purchase contracts have terminated prior to the purchase contract settlement date, transfer the pledged securities included in the Corporate Units or Treasury Units evidenced by the certificate.

Governing Law

The purchase contracts and the purchase contract and pledge agreement and the remarketing agreement will be governed by, and construed in accordance with, the laws of the State of New York (without regard to conflicts of laws principles thereof).

Information Concerning the Purchase Contract Agent

U.S. Bank (or its successor) will be the purchase contract agent. The purchase contract agent will act as the agent for the holders of Corporate Units and Treasury Units. The purchase contract agent will not be obligated to take any discretionary action in connection with a default under the terms of the Corporate Units, the Treasury Units or the purchase contract and pledge agreement.

The purchase contract and pledge agreement will contain provisions limiting the liability of the purchase contract agent. The purchase contract and pledge agreement also will contain provisions under which the purchase contract agent may resign or be replaced. Such resignation or replacement will be effective upon the appointment of a successor.

In addition to serving as the purchase contract agent and collateral agent, as described below, U.S. Bank will serve as the custodial agent and securities intermediary under the purchase contract and pledge agreement and as the “indenture trustee” under the indenture for the notes. We and certain of our affiliates maintain banking and credit relationships with U.S. Bank. U.S. Bank also serves as trustee of some of our pension plans. U.S. Bank and its affiliates have purchased, and are likely to purchase in the future, our securities and securities of our affiliates.

Information Concerning the Collateral Agent

U.S. Bank (or its successor) will be the collateral agent. The collateral agent will act solely as our agent and will not assume any obligation or relationship of agency or trust for or with any of the holders of the Corporate Units and the Treasury Units except for the obligations owed by a pledgee of property to the owner thereof under the purchase contract and pledge agreement and applicable law.

The purchase contract and pledge agreement will contain provisions limiting the liability of the collateral agent. The purchase contract and pledge agreement also will contain provisions under which the collateral agent may resign or be replaced. Such resignation or replacement will be effective upon the appointment of a successor.

Miscellaneous

The purchase contract and pledge agreement will provide that we will indemnify the purchase contract agent and pay all fees and expenses related to (1) the retention of the purchase contract agent, the collateral agent, the custodial agent and the securities intermediary and (2) any enforcement by the purchase contract agent of the rights of the holders of the Corporate Units and Treasury Units. Holders who elect to substitute the related pledged securities, thereby creating Treasury Units or recreating Corporate Units, however, will be responsible for any fees or expenses payable in connection with such substitution, as well as for any commissions, fees or

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other expenses incurred in acquiring the pledged securities to be substituted. We will not be responsible for any such fees or expenses. The purchase contract agent shall be under no obligation to exercise any of the rights or powers vested in it by the purchase contract and pledge agreement at the request or direction of any of the holders pursuant to the purchase contract and pledge agreement, unless such holders shall have offered to the purchase contract agent security or indemnity reasonably satisfactory to the purchase contract agent against the costs, expenses and liabilities which might be incurred by it in compliance with such request or direction.

The purchase contract and pledge agreement will also provide that any court of competent jurisdiction may in its discretion require, in any suit for the enforcement of any right or remedy under the purchase contract and pledge agreement, or in any suit against the purchase contract agent for any action taken, suffered or omitted by it as purchase contract agent, the filing by any party litigant in such suit of an undertaking to pay the costs of such suit, and that such court may in its discretion assess reasonable costs, including reasonable attorneys’ fees and costs against any party litigant in such suit, having due regard to the merits and good faith of the claims or defenses made by such party litigant. The foregoing shall not apply to any suit instituted by the purchase contract agent, to any suit instituted by any holder, or group of holders, holding in the aggregate more than 10% of the outstanding Equity Units, or to any suit instituted by any holder for the enforcement of any interest on any notes owed pursuant to such holder’s applicable ownership interests in notes or contract adjustment payments on or after the respective payment date therefor in respect of any Equity Unit held by such holder, or for enforcement of the right to purchase shares of our common stock under the purchase contracts constituting part of any Equity Unit held by such holder.

Book-Entry System

The Depository Trust Company, or DTC, which we refer to along with its successors in this capacity as the “depository,” will act as securities depository for the Corporate Units and Treasury Units. The Corporate Units and Treasury Units will be issued only as fully registered securities registered in the name of Cede & Co., the depository’s nominee, or such other name as may be requested by an authorized representative of DTC. One or more fully registered global security certificates, representing the total aggregate number of Corporate Units and Treasury Units, will be issued and will be deposited with the depository or its custodian and will bear a legend regarding the restrictions on exchanges and registration of transfer referred to below.

The laws of some jurisdictions may require that some purchasers of securities take physical delivery of securities in definitive form. These laws may impair the ability to transfer beneficial interests in the Corporate Units and Treasury Units so long as the Corporate Units and Treasury Units are represented by global security certificates.

DTC advises that it is a limited-purpose trust company organized under the New York Banking Law, a “banking organization” within the meaning of the New York Banking Law, a member of the Federal Reserve System, a “clearing corporation” within the meaning of the New York Uniform Commercial Code and a “clearing agency” registered pursuant to the provisions of Section 17A of the Exchange Act. The depository holds securities that its participants (“direct participants”) deposit with the depository. The depository also facilitates the post-trade settlement among direct participants of sales and other securities transactions in deposited securities through electronic computerized book-entry transfers and pledges between participants’ accounts, thereby eliminating the need for physical movement of securities certificates. Direct participants include U.S. and Non-U.S. securities brokers and dealers, banks, trust companies, clearing corporations and certain other organizations. The depository is a wholly-owned subsidiary of The Depository Trust & Clearing Corporation (“DTCC”). DTCC is the holding company for DTC, National Securities Clearing Corporation, and Fixed Income Clearing Corporation, all of which are registered clearing agencies. DTCC is owned by the users of its regulated subsidiaries. Access to the depository’s system is also available to others, including securities brokers and dealers, banks, trust companies and clearing corporations that clear transactions through or maintain a custodial relationship with a direct participant, either directly or indirectly. The rules applicable to the depository and its participants are on file with the SEC.

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If (1) the depository notifies us that it is unwilling or unable to continue its services as depository and no successor depository has been appointed within 90 days after our receipt of such notice; (2) the depository ceases to be a clearing agency registered under the Exchange Act when the depository is required to be so registered and we receive notice of such cessation, and no successor depository has been appointed within 90 days after our receipt of such notice or our becoming aware of such cessation; or (3) any Event of Default (as defined in “Description of the Notes—Events of Default”) has occurred and is continuing or any other event has occurred and is continuing, which after notice or lapse of time, would become an Event of Default with respect to the notes, or we have failed to perform any of our obligations under the purchase contract and pledge agreement, the Corporate Units, the Treasury Units or the purchase contracts, and any beneficial owner requests that its beneficial interest be exchanged for a physical certificate, then (x) we will prepare definitive certificates with respect to such Corporate Units or Treasury Units, as applicable, and will deliver such certificates to the purchase contract agent and (y) upon surrender of the global security certificates representing Corporate Units or Treasury Units by the depository, accompanied by registration instructions, we will cause definitive certificates to be delivered to the beneficial owners in accordance with instructions provided by the depository. We and the purchase contract agent will not be liable for any delay in delivery of such instructions and may conclusively rely on, and will be authorized and protected in relying on, such instructions. Each definitive certificate so delivered will evidence Corporate Units or Treasury Units, as applicable, of the same kind and tenor as the global security certificate so surrendered in respect thereof.

As long as the depository or its nominee is the registered owner of the global security certificates, the depository or its nominee, as the case may be, will be considered the sole owner and holder of the global security certificates and all Corporate Units and Treasury Units represented by these certificates for all purposes under the Corporate Units, Treasury Units and the purchase contract and pledge agreement. Except in the limited circumstances referred to above, owners of beneficial interests in global security certificates:

All payments on the Corporate Units and Treasury Units represented by the global security certificates and all transfers and deliveries of related notes, Treasury securities and common stock will be made to the depository or its nominee, as the case may be, as the holder of the securities.

Ownership of beneficial interests in the global security certificates will be limited to participants or persons that may hold beneficial interests through institutions that have accounts with the depository or its nominee. Ownership of beneficial interests in global security certificates will be shown only on, and the transfer of those ownership interests will be effected only through, records maintained by the depository or its nominee, with respect to participants’ interests, or any participant, with respect to interests of persons held by the participant on their behalf. Procedures for settlement of purchase contracts on the purchase contract settlement date or upon early settlement will be governed by arrangements among the depository, participants and persons that may hold beneficial interests through participants designed to permit settlement without the physical movement of certificates. Payments, transfers, deliveries, exchanges and other matters relating to beneficial interests in global security certificates may be subject to various policies and procedures adopted by the depository from time to time. None of us, the purchase contract agent or any agent of us or the purchase contract agent will have any responsibility or liability for any aspect of the depository’s or any participant’s records relating to, or for payments made on account of, beneficial interests in global security certificates, or for maintaining, supervising or reviewing any of the depository’s records or any participant’s records relating to these beneficial ownership interests.

Although the depository has agreed to the foregoing procedures in order to facilitate transfers of interest in the global security certificates among participants, the depository is under no obligation to perform or continue to

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perform these procedures, and these procedures may be discontinued at any time. We will not have any responsibility for the performance by the depository or its direct participants or indirect participants under the rules and procedures governing the depository.

The information in this section concerning the depository and its book-entry system has been obtained from sources that we believe to be reliable, but we have not attempted to verify the accuracy of this information.

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DESCRIPTION OF THE NOTES

In this Description of the Notes, “Spire,” “we,” “us,” “our” and the “Company” refer only to Spire Inc. and any successor obligor, and not to any of its subsidiaries.

The following summary description sets forth certain terms and provisions of the 2021 Series A 0.75% remarketable senior notes due 2026 (the “notes”), and to the extent inconsistent therewith replaces the description of the general terms and provisions of the senior debt securities set forth in the accompanying base prospectus, to which we refer you. Because this description is a summary, it does not describe every aspect of the notes and should be read together with the forms of notes, the indenture (as defined under “Description of the Notes—Ranking”) under which the notes will be issued, the supplemental indenture (as defined under “Description of the Notes—Ranking”) establishing the terms of the notes. The indenture is filed as an exhibit to, and incorporated by reference in, the registration statement of which the accompanying base prospectus is a part. In this summary, we refer to the indenture, as supplemented by the supplemental indenture, together, as the “indenture.”

The indenture and its associated documents contain the full legal text of the matters described in this section. The indenture has been qualified under the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”), and you should refer to the Trust Indenture Act for provisions that apply to the notes.

General

We will issue the notes as debt securities under the indenture. We may issue an unlimited amount of other securities under the indenture which are on parity with the notes.

The notes will be our unsecured and unsubordinated obligations and will rank on a parity in right of payment with all of our other unsecured and unsubordinated indebtedness from time to time outstanding. Additional information about our current outstanding indebtedness and the relative priorities of our indebtedness is described below under “—Ranking.”

The notes will be issued in fully registered form only, without coupons. Any notes that are issued as separate securities as a result of the creation of Treasury Units or in connection with an early settlement, early settlement upon a fundamental change, a remarketing, a termination or a settlement with separate cash will be initially represented by one or more fully registered global securities (the “global securities”) deposited with the indenture trustee, as custodian for DTC, as depository, and registered in the name of DTC or DTC’s nominee. A beneficial interest in a global security will be shown on, and transfers or exchanges thereof will be effected only through, records maintained by DTC and its participants, as described below under “—Book-Entry Issuance—The Depository Trust Company.” The authorized denominations of the notes will be $1,000 and any larger amount that is an integral multiple of $1,000. However, if a holder is entitled to receive notes in an aggregate principal amount that is not an integral multiple of $1,000 upon termination of the purchase contracts as described under “Description of the Purchase Contracts—Termination” above, we will issue upon request the purchase contract agent notes in denominations of $50 and integral multiples thereof. Except in certain circumstances described below, the notes that are issued as global securities will not be exchangeable for notes in definitive certificated form.

Each Corporate Unit includes a 1/20th, or 5%, undivided beneficial ownership interest in a note having a principal amount of $1,000 that corresponds to the stated amount of $50 per Corporate Unit.

The notes will not be subject to a sinking fund provision and, prior to the purchase contract settlement date, will not be subject to defeasance. After the purchase contract settlement date, the notes will be subject to defeasance as described under “Description of Debt Securities—Senior Debt Securities—Satisfaction and

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Discharge” in the accompanying base prospectus. The entire principal amount of the notes will mature and become due and payable, together with any accrued and unpaid interest thereon, on March 1, 2026. As described below under “—Put Option upon Failed Remarketing,” holders will have the right to require us to purchase their notes under certain circumstances. Except as set forth under “—Put Option upon Failed Remarketing,” the indenture will not contain any financial covenants or restrict us from paying dividends, making investments, incurring indebtedness or repurchasing our securities. Except for the covenants described under “—Consolidation, Merger or Sale,” the indenture does not contain provisions that afford holders of the notes protection in the event we are involved in a highly leveraged transaction or other similar transaction that may adversely affect such holders. The indenture does not limit our ability to issue or incur other debt or issue preferred stock.

The notes are initially being offered in the principal amount of $160,000,000. If we issue additional Corporate Units as a result of the underwriters’ exercise of their option to buy additional Corporate Units, we will, without the consent of the holders of the notes, increase the principal amount of the notes and issue up to an additional $15,000,000 principal amount of notes having the same ranking, interest rate, maturity and other terms as the notes. Any such new notes, together with the existing notes, will constitute a single class of securities under the indenture. The existing notes and any new notes having the same terms as the notes offered hereby subsequently issued under the indenture will be treated as a single class for all purposes under the indenture, including, without limitation, voting waivers and amendments.

We will not pay any additional amounts to holders of the notes in respect of any tax, assessment or governmental charge.

Ranking

The notes will be issued by us under an indenture (the “base indenture”) between us and U.S. Bank (referred to herein as the “indenture trustee”), as supplemented by a supplemental indenture, the terms of which are described in this prospectus supplement (the “supplemental indenture” and, together with the base indenture, the “indenture”). We may issue under the base indenture additional debt securities that rank on parity with to the notes.

The notes will be will be our unsecured and unsubordinated obligations and will rank on a parity in right of payment with all of our other unsecured and unsubordinated indebtedness from time to time outstanding. The notes will also be effectively subordinated to all liabilities of our subsidiaries. See “Description of Debt Securities—Senior Debt Securities—Ranking” in the accompanying base prospectus.

Because we are a holding company and conduct all of our operations through our subsidiaries, our ability to meet our obligations under the notes is dependent on the earnings and cash flows of those subsidiaries and the ability of those subsidiaries to pay dividends or to advance or repay funds to us. Holders of the notes will generally have a junior position to claims of creditors of our subsidiaries, including trade creditors, debtholders, secured creditors, taxing authorities, guarantee holders and any preferred stockholders. As of December 31, 2020, we had $690.0 million principal amount of outstanding long-term debt that would rank on parity with the notes and had no outstanding indebtedness that would rank junior to the notes, in each case, on an unconsolidated basis. Additionally, as of December 31, 2020, our subsidiaries had approximately $1,954.6 million principal amount of outstanding debt to external sources (including securities due within one year), which would be structurally senior to the notes.

Principal and Interest

The notes will mature on March 1, 2026 (the “stated maturity date”) and will initially bear interest from the date of original issuance at the rate of 0.75% per annum. Subject to the changes to the interest payment dates made pursuant to a successful remarketing, interest will be payable quarterly on March 1, June 1, September 1 and December 1 of each year (each, an “interest payment date”), commencing on June 1, 2021, and at maturity.

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Subject to certain exceptions, the indenture provides for the payment of interest on an interest payment date only to persons in whose names the notes are registered at the close of business on the record date; which will be the close of business on the 15th day of the calendar month immediately preceding the calendar month in which the applicable interest payment date falls (whether or not a business day). Notwithstanding the foregoing, any interest payable at maturity will be paid to the person to whom principal is payable. Interest will be calculated on the basis of a 360-day year of twelve 30-day months, and with respect to any period less than a full calendar month, on the basis of the actual number of days elapsed in a 30-day month.

If any interest payment date, redemption date, maturity date or the date (if any) on which we are required to purchase the notes is not a business day, then the applicable payment will be made on the next succeeding day that is a business day, and no interest will accrue or be paid in respect of such delay. “Business day,” for purposes of the indenture, means any day that is not a Saturday or Sunday or a day on which banking institutions in The City of New York are authorized or required by law or executive order to close or a day on which the corporate trust office of the indenture trustee is closed for business.

The interest rate on the notes may be reset in connection with a successful remarketing, as described below under “—Interest Rate Reset.” However, if there is not a successful remarketing, the interest rate will not be reset and the notes will continue to bear interest at the initial interest rate, all as described below under “—Interest Rate Reset.” Except in the case of a failed final remarketing, interest on the notes following the optional remarketing settlement date or the purchase contract settlement date, as applicable, will be payable on a semi-annual basis.

Remarketing

The notes will be remarketed as described under “Description of the Purchase Contracts—Remarketing.”

Following any successful remarketing of the notes:

All such modifications will take effect only if the remarketing is successful, without the consent of holders, on the optional remarketing settlement date or the purchase contract settlement date, as the case may be, and will apply to all notes, whether or not included in the remarketing. All other terms of the notes will remain unchanged.

We will use commercially reasonable efforts to ensure that, if required by applicable law, a registration statement, including a prospectus, with regard to the full amount of the notes to be remarketed will be effective under the securities laws in a form that may be used by the remarketing agent in connection with the remarketing (unless a registration statement is not required under the applicable laws and regulations that are in effect at that time or unless we conduct any remarketing in accordance with an exemption under the securities laws).

In order to remarket the notes, we may, in consultation with the remarketing agent, reset the interest rate on the notes (either upward or downward) in order to produce the required price in the remarketing, as discussed under “Description of the Purchase Contracts—Remarketing.”

Remarketing of Notes That Are Not Included in Corporate Units

At any time after we give notice of a remarketing (other than during a blackout period), holders of notes that do not underlie Corporate Units may elect to have their notes remarketed in such remarketing in the same manner

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as notes that underlie Corporate Units by delivering their notes along with a notice of this election to the custodial agent. The custodial agent will hold the notes separate from the collateral account in which the pledged securities will be held. Holders of notes electing to have their notes remarketed will also have the right to make or withdraw such election at any time on or prior to 4:00 p.m., New York City time, on the second business day immediately preceding the first day of an optional remarketing period or final remarketing period, as the case may be, in each case, other than during a blackout period. In the event of a successful remarketing during the optional remarketing period, each holder of separate notes that elects to have its notes remarketed will receive, for each $1,000 principal amount of notes sold, the remarketing price per note. The “remarketing price per note” means, for each $1,000 principal amount of notes, an amount in cash equal to the quotient of the remarketing Treasury portfolio purchase price divided by the number of notes having a principal amount of $1,000 included in such remarketing that are held as components of Corporate Units. For the purposes of determining the proceeds that the remarketing agent will seek to obtain for the notes in an optional remarketing, the “separate notes purchase price” means the amount in cash equal to the product of (1) the remarketing price per note and (2) the number of notes having a principal amount of $1,000 included in such remarketing that are not part of Corporate Units. In the event of a successful remarketing during the final remarketing period, each holder of separate notes that elects to have its notes remarketed will receive an amount, for each $1,000 principal amount of notes, equal to $1,000 in cash. Any accrued and unpaid interest on such notes, will be paid in cash by us, on the purchase contract settlement date.

Interest Rate Reset

In the case of a successful remarketing, the interest rate on the notes may be reset on the date of a successful remarketing and the relevant reset rate will become effective on the settlement date of the remarketing, which will be, in the case of an optional remarketing, the second business day following the optional remarketing date (or, if the remarketed notes are priced after 4:30 p.m. New York time on the optional remarketing date, the third business day following the optional remarketing date) and, in the case of the final remarketing period, the purchase contract settlement date. If a reset occurs pursuant to a successful optional remarketing, the reset rate will be the interest rate determined by us, in consultation with the remarketing agent, as the rate the notes should bear in order for the remarketing proceeds to equal at least 100% of the remarketing Treasury portfolio purchase price plus the separate notes purchase price, if any. If a reset occurs pursuant to a successful final remarketing, the reset rate will be the interest rate determined by us, in consultation with the remarketing agent, as the rate the notes should bear in order for the remarketing proceeds to equal at least 100% of the principal amount of the notes being remarketed. In any case, a reset rate may be higher or lower than the initial interest rate of the notes depending on the results of the remarketing and market conditions at that time. However, in no event will the reset rate exceed the maximum rate permitted by applicable law. In addition, following a successful remarketing, interest on notes will be payable on a semi-annual basis on March 1 and September 1 of each year.

If the notes are not successfully remarketed, the interest rate will not be reset and the notes will continue to bear interest at the initial annual interest rate of 0.75%.

The remarketing agent is not obligated to purchase any notes that would otherwise remain unsold in the remarketing. None of the Company, the remarketing agent or any agent of the Company or the remarketing agent will be obligated in any case to provide funds to make payment upon tender of notes for remarketing.

Put Option upon Failed Remarketing

If the notes have not been successfully remarketed on or prior to the last day of the final remarketing period, unless a special event redemption has previously occurred, holders of notes will have the right to require us to purchase their notes on the purchase contract settlement date, upon at least one business day’s prior notice in the case of notes that are not included in Corporate Units, at a price equal to the principal amount of such notes plus accrued and unpaid interest to, but excluding, the redemption date. In such circumstances, holders of notes that

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underlie Corporate Units will be deemed to have exercised such put right as described under “Description of the Purchase Contracts—Final Remarketing,” unless they settle the related purchase contracts with separate cash.

Redemption at Our Option

Except in the case of the occurrence and continuance of a special event redemption as described below, we may redeem the notes at our option only if there has been a failed final remarketing. In that event, any notes that remain outstanding after the purchase contract settlement date will be redeemable on or after June 1, 2024 at our option, in whole or in part, at any time and from time to time, at a redemption price equal to the principal amount thereof plus accrued and unpaid interest, if any, to but excluding the redemption date. We may at any time irrevocably waive the right to redeem the notes for any specified period (including the remaining term of the notes). We may not redeem the notes if the notes have been accelerated and such acceleration has not been rescinded or unless all accrued and unpaid interest has been paid in full on all outstanding notes for all interest periods terminating on or prior to the redemption date. Following a successful remarketing of the notes, the notes will cease to be redeemable at our option.

Redemption Procedures

We will send notice of any optional redemption to the registered holder of the notes being redeemed not less than 30 days and not more than 60 days before the redemption date. The notice of redemption will identify, among other things, the redemption date, the redemption price and that on the redemption date, the redemption price will become due and payable and that notes called for redemption will cease to accrue interest on and after the redemption date (unless there is a default on payment of the redemption price). Prior to the redemption date, we will deposit with the paying agent or the indenture trustee money sufficient to pay the redemption price of the notes to be redeemed on that date. If we redeem less than all of the notes, and the notes are issued as global securities, the notes to be redeemed will be selected by DTC in accordance with applicable DTC procedures. If the notes to be redeemed are not issued as global securities, the indenture trustee will choose the notes to be redeemed by lot or in any manner that it deems fair.

In the event the final remarketing fails and you do not settle the related purchase contracts with separate cash, if you hold notes as part of Corporate Units you will be deemed to exercise your option to put the notes to us unless you elect to settle the purchase contracts with separate cash as described under “Description of the Purchase Contracts—Notice to Settle with Cash,” and we will apply the put price against your obligations under the purchase contracts. This remedy has the effect similar to an automatic redemption of the notes, but we do not have to give you prior notice or follow any of the other redemption procedures.

We may block the transfer or exchange of (i) all notes during a period of 15 days prior to the date on which notice of selection of the notes for optional redemption is given or (ii) any note being redeemed, except with respect to the unredeemed portion of any note being redeemed solely in part.

The “Description of Debt Securities—General—Redemption” section of the accompanying base prospectus does not apply to the notes.

Special Event Redemption

If a special event occurs and is continuing, we may, at our option, redeem the notes in whole but not in part at any time at a price, which is referred to as the “special event redemption price,” equal to, for each note, the special event redemption amount described below plus accrued and unpaid interest, if any, to, but excluding the date of redemption. Installments of interest on notes which are due and payable on or prior to a redemption date will be payable to the holders of the notes registered as such at the close of business on the relevant record dates. If, following the occurrence of a special event, we exercise our option to redeem the notes, the proceeds of the redemption will be payable in cash to the holders of the notes which are not part of Corporate Units. If the special

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event redemption occurs prior to a successful remarketing of the notes, or if the notes are not successfully remarketed, prior to the purchase contract settlement date, the special event redemption price for the notes that are components of the Corporate Units at the time of the special event redemption will be distributed to the collateral agent, who in turn will purchase the Treasury portfolio described below on behalf of the holders of Corporate Units and remit the remainder of the redemption price, if any, to the purchase contract agent for payment to the holders. Thereafter, the applicable ownership interests in the Treasury portfolio will be substituted for the applicable ownership interests in the notes and the treasury securities referred to in the first clause of the “special event Treasury portfolio” described below will be pledged to us through the collateral agent to secure the Corporate Unit holders’ obligations to purchase our common stock under the purchase contracts.

“Special event” means either an accounting event or a tax event, each as defined below.

“Accounting event” means the receipt by the audit committee of our board of directors (or, if there is no such committee, by such board of directors) of a written report in accordance with Statement on Auditing Standards (“SAS”) No. 97, “Amendment to SAS No. 50—Reports on the Application of Accounting Principles,” from our independent auditors, provided at the request of our management, to the effect that, as a result of a change in accounting rules that becomes effective after the date of original issuance of the notes, we must either (1) account for the purchase contracts as derivatives (or otherwise mark-to-market or measure the fair value of all or any portion of the purchase contracts with changes appearing in our income statement) or (2) account for the Equity Units using the if-converted method, and that such accounting treatment will cease to apply upon redemption of the notes.

“Tax event” means the receipt by us of an opinion of nationally recognized independent tax counsel experienced in such matters to the effect that there is more than an insubstantial risk that interest payable by us on the notes would not be deductible, in whole or in part, by us for U.S. federal income tax purposes as a result of any amendment to, change in, or announced proposed change in, the laws, or any regulations thereunder, of the United States or any political subdivision or taxing authority thereof or therein affecting taxation, any amendment to or change in an interpretation or application of any such laws or regulations by any legislative body, court, governmental agency or regulatory authority or any interpretation or pronouncement by any legislative body, court, governmental agency or regulatory authority that provides for a position with respect to any such laws or regulations that differs from the generally accepted position on the date of this prospectus supplement, which amendment, change or proposed change is effective or which interpretation or pronouncement is announced on or after the date of this prospectus supplement.

“Special event redemption amount” means

Depending on the special event Treasury portfolio purchase price, the special event redemption amount could be less than or greater than the principal amount of the note.

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As used in this context, “special event Treasury portfolio purchase price” means the lowest aggregate price quoted by a primary U.S. government securities dealer in New York City to the quotation agent on the business day immediately preceding the special event redemption date for the purchase of the special event Treasury portfolio for settlement on the special event redemption date.

“Special event Treasury portfolio”, means the Treasury portfolio to be purchased in connection with a special event redemption, which will consist of:

Notice of any redemption will be mailed at least 30 days but not more than 60 days before the redemption date to each registered holder of notes to be redeemed at its registered address. Unless we default in payment of the redemption price, on and after the redemption date interest shall cease to accrue on the notes. In the event any notes are called for redemption, neither we nor the indenture trustee will be required to register the transfer of or exchange the notes to be redeemed.

Events of Default

The Events of Default and related provisions set forth under “Description of Debt Securities—Senior Debt Securities—Events of Default” in the accompanying base prospectus will apply to the notes. In addition, an “Event of Default” with respect to the notes will occur if we fail to pay the purchase price of any note on the purchase contract settlement date, if required under “—Put Option upon Failed Remarketing” above.

The holders of a majority in principal amount of outstanding notes may waive a default or Event of Default, other than a default in the payment of principal of, or interest on, the notes (including the redemption price or purchase price of the notes, if applicable), or a default or Event of Default with respect to a covenant or provision that cannot be modified or amended without the consent of the holder of each outstanding note.

If any portion of the amount payable on the notes upon acceleration is considered by a court to be unearned interest, the court could disallow recovery of such portion.

Consolidation, Merger or Sale

We will agree not to merge or consolidate with any other corporation or sell or convey all or substantially all of our assets to any person unless (i) either we are the continuing corporation, or the successor corporation (if other than us) is a corporation organized and existing under the laws of the United States of America or a State thereof or the District of Columbia and such corporation expressly assumes the due and punctual payment of the principal of and interest on the notes, and the due and punctual performance and observance of all of the covenants and conditions of the indenture to be performed by us by supplemental indenture in form satisfactory to the indenture trustee, executed and delivered to the indenture trustee by such corporation, and (ii) we or such successor corporation, as the case may be, will not, immediately after such merger or consolidation, or such sale or conveyance, be in default in the performance of any such covenant or condition.

In case of any such consolidation, merger or conveyance, such successor corporation will succeed to and be substituted for us, with the same effect as if it had been named as us in the indenture, and in the event of such conveyance (other than by way of a lease), we will be discharged of all of our obligations and covenants under the indenture and the notes.

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This “—Consolidation, Merger or Sale” section replaces the “Description of Debt Securities—General—Consolidation, Merger or Sale of Assets” section of the accompanying base prospectus in its entirety.

Modification of Indenture

Without Holder Consent

Without the consent of any holders of notes, we and the indenture trustee may from time to time amend or supplement the indenture and the notes for the following purposes:

With Holder Consent

Under the indenture, supplemental indentures for the purposes of adding any provisions to or changing in any manner or eliminating any of the provisions of the indenture or of modifying in any manner the rights of the holders of the notes under the indenture may be entered into by us, when authorized by board resolution, and the indenture trustee, with the consent of the holders of not less than a majority in principal amount of the notes. However, no such supplemental indenture shall:

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For the avoidance of doubt, the immediately preceding sentence will not limit our ability to modify the terms of the notes in connection with a remarketing that is made in accordance with the terms of the indenture.

A supplemental indenture that changes or eliminates any covenant or other provision of the indenture expressly included solely for the benefit of holders of securities other than the notes, or which modifies the rights of the holders of securities other than the notes with respect to such covenant or other provision, will be deemed not to affect the rights under the indenture of the holders of the notes.

We may omit to comply with any covenant or condition contained in the indenture if holders of a majority in principal amount of the notes waive such compliance.

The “Description of Debt Securities—Senior Debt Securities—Modification and Waiver” section of the accompanying base prospectus does not apply to the notes.

Title

Prior to due presentment for registration of transfer of any note, we, the indenture trustee and any agent of ours or the indenture trustee may deem and treat the person in whose name such note is registered as the absolute owner of such note (whether or not payments in respect of such note are overdue and notwithstanding any notation of ownership or other writing thereon) for the purpose of receiving payment of or an account of the principal of and interest on such note and for all other purposes; and neither we nor the indenture trustee nor any agent of ours or the indenture trustee will be affected by any notice to the contrary.

Governing Law

The indenture and the notes provide that they will be governed by and for all purposes construed in accordance with the laws of the State of New York (without regard to conflicts of laws principles thereof).

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The Indenture Trustee

The trustee under the indenture will be U.S. Bank. We and certain of our affiliates maintain banking and credit relationships with U.S. Bank. U.S. Bank also serves as trustee of some of our pension plans. U.S. Bank and its affiliates have purchased, and are likely to purchase in the future, our securities and securities of our affiliates.

Book-Entry Issuance—The Depository Trust Company

The notes that form a part of the Corporate Units will be issued in fully registered form and will be registered in the name of the purchase contract agent. The notes that do not form a part of the Corporate Units will be evidenced by one or more global notes registered in the name of DTC’s nominee, Cede & Co., or such other name as may be requested by an authorized representative of DTC. Such global notes will be deposited with the indenture trustee as custodian for DTC. See “Certain Provisions of the Purchase Contract and Pledge Agreement—Book-Entry System” for a description of DTC.

Purchases of the notes under the DTC system must be made by or through direct participants, which will receive a credit for the notes on DTC’s records. The ownership interest of each actual purchaser of each note (“beneficial owner”) is in turn to be recorded on the direct and indirect participants’ records. Beneficial owners will not receive written confirmation from DTC of their purchases, but beneficial owners are expected to receive written confirmations providing details of the transactions, as well as periodic statements of their holdings, from the direct or indirect participant through which they purchased the notes. Transfers of ownership interests on the notes are to be accomplished by entries made on the books of direct and indirect participants acting on behalf of beneficial owners. Beneficial owners will not receive certificates representing their ownership interests in notes, except in the event that use of the book-entry system for the notes is discontinued.

To facilitate subsequent transfers, all notes deposited by direct participants with DTC are registered in the name of DTC’s nominee, Cede & Co., or such other name as may be requested by an authorized representative of DTC. The deposit of the notes with DTC and their registration in the name of Cede & Co. or such other nominee do not effect any change in beneficial ownership. DTC has no knowledge of the actual beneficial owners of the notes; DTC’s records reflect only the identity of the direct participants to whose accounts the notes are credited, which may or may not be the beneficial owners. The direct and indirect participants will remain responsible for keeping account of their holdings on behalf of their customers.

Conveyance of notices and other communications by DTC to direct participants, by direct participants to indirect participants, and by direct participants and indirect participants to beneficial owners, will be governed by arrangements among them, subject to any statutory or regulatory requirements as may be in effect from time to time. Notices will be sent to DTC.

Neither DTC nor Cede & Co. (nor such other DTC nominee) will consent or vote with respect to the notes unless authorized by a direct participant in accordance with DTC’s procedures. Under its usual procedures, DTC mails an omnibus proxy to us as soon as possible after the record date. The omnibus proxy assigns the voting or consenting rights of Cede & Co. to those direct participants to whose accounts the notes are credited on the record date. We believe that these arrangements will enable the beneficial owners to exercise rights equivalent in substance to the rights that can be directly exercised by a registered holder of the notes.

Payments of principal and interest on the notes will be made to Cede & Co. (or such other nominee of DTC). DTC’s practice is to credit direct participants’ accounts upon DTC’s receipt of funds and corresponding detail information from us or the indenture trustee, on the payable date in accordance with their respective holdings shown on DTC’s records. Payments by participants to beneficial owners will be governed by standing instructions and customary practices and will be the responsibility of each participant and not of DTC, the indenture trustee or us, subject to any statutory or regulatory requirements as may be in effect from time to time. Payment of principal and interest to Cede & Co. (or other such nominee of DTC) is our responsibility. Disbursement of such payments to direct participants will be the responsibility of DTC, and disbursement of such payments to the beneficial owners is the responsibility of direct and indirect participants.

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In a few special situations described below, a book-entry security representing Spire securities will terminate and interests in it will be exchanged for physical certificates representing the securities. After that exchange, the choice of whether to hold securities directly or in street name will be up to you. You must consult your bank, broker or other financial institution to find out how to have your interests in the securities transferred to your name, so that you will be a direct holder.

The special situations for termination of a global security representing the notes are:

DTC may discontinue providing its services as securities depository with respect to the notes at any time by giving us or the indenture trustee reasonable notice. In the event no successor securities depository is obtained, certificates for the notes will be printed and delivered.

The information in this section concerning DTC’s book-entry system has been obtained from sources that we believe to be reliable, but neither we nor the underwriters take any responsibility for the accuracy of this information.

The indenture trustee shall have no obligation or duty to monitor, determine or inquire as to compliance with any restrictions on transfer imposed under the indenture or under applicable law with respect to any transfer of any interest in any note (including any transfers between or among direct participant of DTC or beneficial owners of interests in any note) other than to require delivery of such certificates and other documentation or evidence as are expressly required by, and to do so if and when expressly required by the terms of, the indenture, and to examine the same to determine substantial compliance as to form with the express requirements hereof.

Neither the indenture trustee nor any agent shall have any responsibility or liability for any actions taken or not taken by DTC.

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