GHL Greenhill and Company Inc

You are cordially invited to attend a special meeting (including any adjournments or postponements thereof, which we refer to as the “Special Meeting”) of stockholders of Greenhill & Co., Inc., a Delaware corporation (which we refer to as “Greenhill,” “we,” and “our”) to be held virtually via live webcast on August 16, 2023, beginning at 12:00 p.m., Eastern Time (unless the Special Meeting is adjourned or postponed). You will be able to virtually attend and vote at the Special Meeting by visiting http://www.virtualshareholdermeeting.com/GHL2023SM, and inserting the 16-digit control number included in your proxy card or voting instruction form provided by your bank, broker, trustee, nominee or other holder of record if you hold your shares in “street name.”

On May 22, 2023, Greenhill, Mizuho Americas LLC, a Delaware limited liability company (which we refer to as “Mizuho Americas”), and Blanc Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Mizuho Americas (which we refer to as “Merger Sub”) entered into an Agreement and Plan of Merger (as it may be amended from time to time, which we refer to as the “Merger Agreement”), pursuant to which, and subject to the terms and conditions set forth therein, Merger Sub will merge with and into Greenhill (which we refer to as the “Merger”), with Greenhill continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Mizuho Americas.

The Merger Agreement provides that each share of common stock, par value $0.01 per share, of Greenhill (which we refer to as “Greenhill common stock”) issued and outstanding immediately prior to the effective time of the Merger (which we refer to as the “Effective Time”) (except for shares held by Greenhill as treasury stock, by any of Greenhill’s subsidiaries, by Mizuho Americas or by any of Mizuho Americas’ subsidiaries (including Merger Sub), or by any holder of record or beneficial owner who is entitled to demand appraisal and has properly and validly demanded appraisal of such shares of Greenhill common stock as further described in the accompanying proxy statement pursuant to Section 262 of the General Corporation Law of the State of Delaware, which, in each case, will be treated as described in the Merger Agreement) will, at the Effective Time, automatically be converted into the right to receive $15.00 in cash, without interest, subject to any required tax withholding.

At the Special Meeting, you will be asked to consider and vote on:

The Board of Directors of Greenhill (which we refer to as the “Board of Directors”), after considering the factors more fully described in the enclosed proxy statement, has unanimously: (a) determined that the Merger Agreement and the transactions contemplated thereby, including the Merger, are advisable, fair to and in the best

interests of Greenhill and its stockholders; (b) approved and adopted the Merger Agreement and the transactions contemplated thereby, including the Merger; (c) recommended that Greenhill stockholders adopt the Merger Agreement; and (d) directed that the adoption of the Merger Agreement be submitted for consideration by Greenhill stockholders at the Special Meeting. The Board of Directors unanimously recommends that you vote: (1) “FOR” the Merger Agreement Proposal; (2) “FOR” the Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

The enclosed proxy statement provides detailed information about the Special Meeting, the Merger Agreement and the Merger. A copy of the Merger Agreement is attached as Annex A to the accompanying proxy statement.

The proxy statement also describes the actions and determinations of the Board of Directors in connection with its evaluation of the Merger Agreement and the Merger. You should carefully read and consider the entire enclosed proxy statement and its annexes, including the Merger Agreement, as they contain important information about, among other things, the Merger and how it affects you.

Whether or not you plan to attend the virtual Special Meeting, please sign, date and return, as promptly as possible, the enclosed proxy card in the accompanying prepaid reply envelope or grant your proxy electronically over the Internet or by telephone (in accordance with the instructions detailed in the section of this proxy statement entitled “The Special Meeting—Voting at the Special Meeting”). If you attend the Special Meeting and vote thereat, your vote will revoke any proxy that you have previously submitted.

If you hold your shares in “street name,” you should instruct your bank, broker or other nominee how to vote your shares in accordance with the voting instruction form that you will receive from your bank, broker or other nominee. Your bank, broker or other nominee cannot vote on any of the proposals, including the Merger Agreement Proposal, without your instructions.

Your vote is very important, regardless of the number of shares that you own. We cannot complete the Merger unless the Merger Agreement Proposal is approved by the affirmative vote of the holders of at least a majority of the issued and outstanding shares of Greenhill common stock entitled to vote thereon at the Special Meeting. If you have any questions or need assistance voting your shares, please contact our proxy solicitor:

On behalf of the Board of Directors, I thank you for your support and appreciate your consideration of these matters.

Neither the Securities and Exchange Commission nor any state securities regulatory agency has approved or disapproved the Merger, passed upon the merits or fairness of the Merger or passed upon the adequacy or accuracy of the disclosure in this document. Any representation to the contrary is a criminal offense.

The accompanying proxy statement is dated July 13, 2023, and, together with the enclosed form of proxy card, is first being mailed to Greenhill stockholders on or about July 14, 2023.

Notice is hereby given that a special meeting (including any adjournments or postponements thereof, which we refer to as the “Special Meeting”) of stockholders of Greenhill & Co., Inc., a Delaware corporation (which we refer to as “Greenhill,” “we,” and “our”), will be held virtually via live webcast on August 16, 2023, beginning at 12:00 p.m., Eastern Time (unless the Special Meeting is adjourned or postponed). You will be able to virtually attend and vote at the Special Meeting by visiting http://www.virtualshareholdermeeting.com/GHL2023SM, and inserting the 16-digit control number included in your proxy card or voting instruction form provided by your bank, broker, trustee, nominee or other holder of record if you hold your shares in “street name.”

On May 22, 2023, Greenhill, Mizuho Americas LLC, a Delaware limited liability company (which we refer to as “Mizuho Americas”), and Blanc Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Mizuho Americas (which we refer to as “Merger Sub”) entered into an Agreement and Plan of Merger (as it may be amended from time to time, which we refer to as the “Merger Agreement”), pursuant to which, and subject to the terms and conditions set forth therein, Merger Sub will merge with and into Greenhill (which we refer to as the “Merger”), with Greenhill continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Mizuho Americas.

The Merger Agreement provides that each share of common stock, par value $0.01 per share, of Greenhill (which we refer to as “Greenhill common stock”) issued and outstanding immediately prior to the effective time of the Merger (which we refer to as the “Effective Time”) (except for shares held by Greenhill as treasury stock, by any of Greenhill’s subsidiaries, by Mizuho Americas or by any of Mizuho Americas’ subsidiaries (including Merger Sub), or by any holder of record or beneficial owner who is entitled to demand appraisal and has properly and validly demanded appraisal of such shares of Greenhill common stock as further described in this proxy statement pursuant to Section 262 of the General Corporation Law of the State of Delaware, which, in each case, will be treated as described in the Merger Agreement) will, at the Effective Time, automatically be converted into the right to receive $15.00 in cash, without interest, subject to any required tax withholding.

The Special Meeting is being held for the following purposes:

Only Greenhill stockholders of record as of the close of business on July 10, 2023, are entitled to notice of the Special Meeting and to vote at the Special Meeting or any adjournment, postponement or other delay thereof.

The Board of Directors of Greenhill unanimously recommends that you vote: (1) “FOR” the Merger Agreement Proposal; (2) “FOR” the Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

Whether or not you plan to attend the virtual Special Meeting, please sign, date and return, as promptly as possible, the enclosed proxy card in the accompanying prepaid reply envelope or grant your proxy electronically over the Internet or by telephone (in accordance with the instructions detailed in the section of this proxy statement entitled “The Special Meeting—Voting at the Special Meeting”). If you attend the Special Meeting and vote thereat, your vote will revoke any proxy that you have previously submitted. If you hold your shares in “street name,” you should instruct your bank, broker or other nominee how to vote your shares in accordance with the voting instruction form that you will receive from your bank, broker or other nominee. Your bank, broker or other nominee cannot vote on any of the proposals, including the Merger Agreement Proposal, without your instructions. If you sign, date and mail your proxy card without indicating how you wish to vote, your proxy will be counted as a vote “FOR” the Merger Agreement Proposal, “FOR” the Compensation Proposal and “FOR” the Adjournment Proposal.

WHETHER OR NOT YOU PLAN TO ATTEND THE SPECIAL MEETING, WE ENCOURAGE YOU TO SUBMIT YOUR PROXY AS PROMPTLY AS POSSIBLE: (1) BY TELEPHONE; (2) OVER THE INTERNET; OR (3) BY SIGNING AND DATING THE ENCLOSED PROXY CARD AND RETURNING IT IN THE POSTAGE-PAID ENVELOPE PROVIDED. You may revoke your proxy or change your vote before the Special Meeting in the manner described in the enclosed proxy statement.

If you fail to (1) return your proxy card, (2) grant your proxy electronically over the Internet or by telephone or (3) attend the Special Meeting, your shares will not be counted for purposes of determining whether a quorum is present at the Special Meeting and, if a quorum is present, will have the same effect as a vote “AGAINST” the Merger Agreement Proposal but, assuming a quorum is present, will have no effect on the Compensation Proposal or the Adjournment Proposal.

You should carefully read and consider the entire accompanying proxy statement and its annexes, including the Merger Agreement, along with all of the documents incorporated by reference into the accompanying proxy statement, as they contain important information about, among other things, the Merger and how it affects you. If you have any questions concerning the Merger Agreement, the Merger, the Special Meeting or the accompanying proxy statement, would like additional copies of the accompanying proxy statement or need help voting your shares of Greenhill common stock, please contact our proxy solicitor:

The following questions and answers address some commonly asked questions regarding the Merger, the Merger Agreement and the Special Meeting. These questions and answers may not address all questions that are important to you. You should carefully read and consider the more detailed information contained elsewhere in this proxy statement and the annexes to this proxy statement, including the Merger Agreement, along with all of the documents we refer to in this proxy statement, as they contain important information about, among other things, the Merger and how it affects you. You may obtain the information incorporated by reference in this proxy statement without charge by following the instructions in the section of this proxy statement entitled “Where You Can Find More Information.”

This communication contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, which involve inherent risks and uncertainties. Words such as “believe,” “expect,” “anticipate,” “plan,” “intend,” “foresee,” “should,” “would,” “could,” “may,” “might,” “estimate,” “outlook,” “possible,” “potential” or similar expressions, including the negative thereof, may identify forward-looking statements that involve certain factors, risks and uncertainties that could cause Greenhill’s actual results to differ materially from those anticipated. Such forward-looking statements include but are not limited to statements about the benefits of the Merger, including future financial and operating results, Greenhill’s or Mizuho Americas’ plans, objectives, expectations and intentions, the expected timing of completion of the Merger and other statements that are not historical facts. The following factors, risks and uncertainties could cause actual results to differ materially from forward-looking statements or historical performance:

These factors are not necessarily all of the factors that could cause Greenhill’s actual results, performance, or achievements to differ materially from those expressed in or implied by any of the forward-looking statements. Other unknown or unpredictable factors also could harm Greenhill’s results.

For additional information concerning factors that could cause actual results and events to differ materially from those projected herein, please refer to Greenhill’s Annual Report on Form 10-K for the year ended December 31, 2022 and to other documents filed by Greenhill with the SEC, including subsequent Current Reports on Form 8-K and Quarterly Reports on Form 10-Q. Greenhill is providing the information in this communication as of this date and, except as required by law, assumes no obligation to update or revise the forward-looking statements in this communication because of new information, future events, or otherwise.

The enclosed proxy is solicited on behalf of the Board of Directors for use at the Special Meeting.

The Special Meeting will be held virtually via live webcast on August 16, 2023, beginning at 12:00 p.m., Eastern Time (unless the Special Meeting is adjourned or postponed). You will be able to virtually attend and vote at the Special Meeting by visiting http://www.virtualshareholdermeeting.com/GHL2023SM and inserting the 16-digit control number included in your proxy card or voting instruction form provided by your bank, broker, trustee, nominee or other holder of record if you hold your shares in “street name.”

At the Special Meeting, we will ask Greenhill stockholders to vote on proposals to:

Only Greenhill stockholders as of the Record Date are entitled to notice of the Special Meeting and to vote at the Special Meeting. A list of Greenhill stockholders entitled to vote at the Special Meeting will be available at our principal executive offices located at 1271 Avenue of the Americas, New York, New York 10020, during regular business hours for a period of no less than 10 days before the Special Meeting, as well as on the Special Meeting website. If Greenhill’s headquarters are closed during such period, the list of Greenhill stockholders will be made available for inspection upon request to our Corporate Secretary at 1271 Avenue of the Americas, New York, New York 10020, subject to the satisfactory verification of Greenhill stockholder status. The list will also be available electronically during the Special Meeting on the Special Meeting website. As of the Record Date, there were 18,802,594 shares of Greenhill common stock issued and outstanding and entitled to vote at the Special Meeting.

The presence, in person or by proxy, of the holders of a majority of the outstanding shares of Greenhill common stock on the Record Date and entitled to vote at the Special Meeting will constitute a quorum at the Special Meeting. In the event that a quorum is not present at the Special Meeting, it is expected that the Special Meeting will be adjourned to solicit additional proxies.

If you fail to (1) submit a signed proxy card, (2) grant a proxy electronically over the Internet or by telephone, or (3) attend the Special Meeting, your shares of Greenhill common stock will not be counted for purposes of determining the presence of a quorum. If you hold your shares of Greenhill common stock in “street name,” and you fail to instruct your bank, broker or other nominee on how to vote your shares of Greenhill common stock, such shares of Greenhill common stock will not be counted for purposes of determining the presence of a quorum. However, if you hold shares of Greenhill common stock in “street name” and give voting instructions to your broker, bank or other nominee with respect to at least one of the proposals, but give no instruction as to one or more of the other proposals, then those shares of Greenhill common stock will be deemed present at the Special Meeting for purposes of establishing a quorum at the Special Meeting, will be voted as instructed with respect to any proposal as to which instructions were given, and will not be voted with respect to any other proposal. Abstentions by you or your bank, broker or other nominee will be counted for purposes of determining the presence of a quorum.

Each Greenhill stockholder will be entitled to one vote for each share of Greenhill common stock owned at the close of business on the Record Date.

A so-called “broker non-vote” results when a bank, broker or other nominee returns a valid proxy voting upon at least one matter as to which the bank, broker or other nominee has received voting instructions from the beneficial owner of the shares or as to which the applicable rules provide discretionary authority for the bank, broker or other nominee to vote without such instruction but the bank, broker or other nominee does not vote on a particular proposal because they do not have discretionary authority to vote on the matter and have not received specific voting instructions from the beneficial owner of such shares. The rules applicable to banks, brokers and other nominees only provide brokers with discretionary authority to vote on proposals that are considered “routine,” whereas each of the proposals to be presented at the Special Meeting is considered “non-routine.” As a result no broker will be permitted to vote your shares of Greenhill common stock at the Special Meeting without receiving instructions from you on how to vote your shares. If a beneficial owner does not provide instruction on any of the proposals, then the shares will not be entitled to be voted at the Special Meeting and therefore will be deemed not present and not counted for purposes of establishing a quorum. Failure to instruct your broker on how to vote your shares will have the same effect as a vote “AGAINST” the Merger Agreement Proposal but will have no effect on the Compensation Proposal or the Adjournment Proposal.

As of the Record Date, our executive officers and directors beneficially owned and were entitled to vote, in the aggregate, 5,997,526 shares of Greenhill common stock, representing approximately 31.9% of the shares of Greenhill common stock issued and outstanding on the Record Date.

We currently expect that our executive officers and directors will vote all of their respective shares of Greenhill common stock (1) “FOR” the Merger Agreement Proposal, (2) “FOR” the Compensation Proposal and (3) “FOR” the Adjournment Proposal.

As described in the section of this proxy statement entitled “The Voting Agreement,” Scott L. Bok and the other Specified Stockholders entered into a Voting Agreement with Mizuho Americas and Merger Sub, pursuant to which the Specified Stockholders have agreed, subject to the terms and conditions thereof, to vote all shares of Greenhill common stock owned by them in favor of the adoption of the Merger Agreement and the approval of the transactions contemplated thereby.

You can vote at the virtual Special Meeting, which will be held on August 16, 2023, at 12:00 p.m., Eastern Time, at http://www.virtualshareholdermeeting.com/GHL2023SM (unless the Special Meeting is adjourned or postponed).

You may also authorize the persons named as proxies on the proxy card to vote your shares by returning the proxy card in advance by mail, over the Internet or by telephone. Although Greenhill offers multiple voting methods, Greenhill encourages you to vote over the Internet or by phone as Greenhill believes they are the most cost-effective methods. We also recommend that you vote as soon as possible, even if you are planning to attend the Special Meeting, so that the vote count will not be delayed. Both the Internet and the telephone provide convenient, cost-effective and reliable alternatives to returning your proxy card by mail. If you choose to vote your shares over the Internet or by telephone, there is no need for you to submit your proxy card by mail.

All shares represented by properly signed and dated proxies received by the deadline indicated above will be voted at the Special Meeting in accordance with the instructions of the Greenhill stockholder. Properly signed and dated proxies that do not contain voting instructions will be voted: (1) “FOR” the Merger Agreement Proposal; (2) “FOR” the Compensation Proposal; and (3) “FOR” the Adjournment Proposal. If you indicate on your proxy card that you wish to vote in favor of the Merger Agreement Proposal but do not indicate a choice on the Adjournment Proposal or the Compensation Proposal on a nonbinding advisory basis, your shares of Greenhill common stock will be voted “FOR” each such proposal. Proxy cards that are returned without a signature will not be counted as present at the Special Meeting and cannot be voted.

If your shares are held in “street name” through a bank, broker or other nominee, you may vote through your bank, broker or other nominee by completing and returning the voting form provided by your bank, broker or other nominee or attending the Special Meeting and voting using your control number, or, if you did not obtain a control number, contacting your bank, broker or other nominee to obtain a control number so that you may vote. If such a service is provided, you may vote over the Internet or telephone through your bank, broker or other nominee by following the instructions on the voting form provided by your bank, broker or other nominee. If you do not return your bank’s, broker’s or other nominee’s voting form, do not vote via the Internet or telephone through your bank, broker or other nominee, if possible, or do not attend the Special Meeting and vote thereat, it will have the same effect as if you voted “AGAINST” the Merger Agreement Proposal but, assuming a quorum is present, will not have any effect on the Compensation Proposal or the Adjournment

Proposal (so long as you do not attend the Special Meeting and abstain from voting on any given proposal, which would have the same effect as voting “AGAINST” the Merger Agreement Proposal, the Compensation Proposal and/or the Adjournment Proposal, as applicable).

Any proxy given by a Greenhill stockholder may be revoked before the Special Meeting by doing any of the following:

If you hold your shares of Greenhill common stock in “street name,” you should contact your bank, broker or other nominee for instructions regarding how to change your vote.

Any adjournment, postponement or other delay of the Special Meeting, including for the purpose of soliciting additional proxies, will allow Greenhill stockholders who have already sent in their proxies to revoke them at any time prior to their use at the Special Meeting as adjourned, postponed or delayed.

The Board of Directors has unanimously: (a) determined that the Merger Agreement and the transactions contemplated thereby, including the Merger, are advisable, fair to and in the best interests of Greenhill and its stockholders; (b) approved and adopted the Merger Agreement and the transactions contemplated thereby, including the Merger; (c) recommended that Greenhill stockholders adopt the Merger Agreement; and (d) directed that the adoption of the Merger Agreement be submitted for consideration by Greenhill stockholders at the Special Meeting.

The Board of Directors unanimously recommends that you vote: (1) “FOR” the Merger Agreement Proposal; (2) “FOR” the Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

The Board of Directors is soliciting your proxy, and Greenhill will bear the cost of soliciting proxies. Georgeson has been retained to assist with the solicitation of proxies. Georgeson will be paid approximately $15,000 and will be reimbursed for its reasonable out-of-pocket expenses for these and other advisory services in connection with the Special Meeting. Forms of proxies and proxy materials may also be distributed through brokers, custodians and other like parties to the beneficial owners of shares of Greenhill common stock, in which case these parties will be reimbursed for their reasonable out-of-pocket expenses in accordance with SEC and NYSE regulations. Proxies may also be solicited in person or by telephone, facsimile, electronic mail or other electronic medium by Georgeson or, without additional compensation, by Greenhill or Greenhill’s directors, officers and employees.

Assuming timely satisfaction of necessary closing conditions, including the approval by Greenhill stockholders of the Merger Agreement Proposal, we currently anticipate that the Merger will be consummated by the end of calendar year 2023.

If the Merger is consummated and certain conditions are met, Greenhill stockholders and beneficial owners who continuously hold shares of Greenhill common stock through the Effective Time, do not vote in favor of the adoption of the Merger Agreement and properly demand appraisal of their shares and do not withdraw their demands or otherwise lose their rights to seek appraisal will be entitled to seek appraisal of their shares in connection with the Merger under Section 262 of the DGCL. This means that Greenhill stockholders and beneficial owners may be entitled to have their shares appraised by the Delaware Court of Chancery and to receive payment in cash of the “fair value” of their shares of Greenhill common stock, exclusive of any elements of value arising from the accomplishment or expectation of the Merger, as determined by the Delaware Court of Chancery, together with interest to be paid on the amount determined to be fair value, if any (or in certain circumstances described in further detail in the section of this proxy statement entitled “The Merger—Appraisal Rights,” on the difference between the amount determined to be the fair value and the amount paid by the Surviving Corporation in the Merger to each Greenhill stockholder or beneficial owner entitled to appraisal prior to the entry of judgment in any appraisal proceeding). Due to the complexity of the appraisal process, Greenhill stockholders and beneficial owners who wish to seek appraisal of their shares are encouraged to review Section 262 of the DGCL carefully and to seek the advice of legal counsel with respect to the exercise of appraisal rights.

Greenhill stockholders and beneficial owners considering seeking appraisal should be aware that the fair value of their shares as determined pursuant to Section 262 of the DGCL could be more than, the same as or less than the value of the consideration that they would receive pursuant to the Merger Agreement if they did not seek appraisal of their shares.

To exercise appraisal rights, Greenhill stockholders must: (a) submit a written demand for appraisal to Greenhill before the vote is taken on the adoption of the Merger Agreement; (b) not submit a proxy or otherwise vote in favor of the proposal to adopt the Merger Agreement; (c) continue to hold their shares of Greenhill common stock of record through the Effective Time; and (d) comply with all other procedures for exercising appraisal rights under Section 262 of the DGCL. Failure to follow the procedures specified under Section 262 of the DGCL may result in the loss of appraisal rights. In addition, the Delaware Court of Chancery will dismiss appraisal proceedings in respect of the Merger unless certain stock ownership conditions are satisfied by the Greenhill stockholders and beneficial owners seeking appraisal. The DGCL requirements for exercising appraisal rights are described in further detail in the section of this proxy statement entitled “The Merger—Appraisal Rights,” which is qualified in its entirety by Section 262 of the DGCL, the relevant section of the DGCL regarding appraisal rights. A copy of Section 262 of the DGCL is reproduced and attached as Annex D to this proxy statement and may be accessed without subscription or cost at the Delaware Code Online (available at https://delcode.delaware.gov/title8/c001/sc09/index.html#262). If you are a beneficial owner who holds your shares of Greenhill common stock through a bank, broker or other nominee and you wish to exercise appraisal rights, you may make a written demand for appraisal in your own name, but you must satisfy the conditions set forth above and your written demand must also reasonably identify the holder of record of the shares for which demand is made, be accompanied by documentary evidence of your beneficial ownership of stock (such as a brokerage or securities account statement containing such information or a letter from a broker or other record holder of such shares confirming such information) and a statement that such documentary evidence is a true and correct copy of what it purports to be, and provide an address at which you consent to receive notices given by the Surviving Corporation under Section 262 of the DGCL and to be set forth on the verified list required by Section 262(f) of the DGCL. For more information, please see the section of this proxy statement entitled “The Merger—Appraisal Rights.”

If the Merger is completed, the shares of Greenhill common stock will be delisted from the NYSE and deregistered under the Exchange Act, and shares of Greenhill common stock will no longer be publicly traded.

Pursuant to the DGCL and Greenhill’s bylaws, only the matters set forth in the Notice of Special Meeting may be brought before the Special Meeting.

Unless we have received contrary instructions, we may send a single copy of this proxy statement to any household at which two or more Greenhill stockholders reside if we believe the stockholders are members of the same family. Each Greenhill stockholder in the household will continue to receive a separate proxy card. This process, known as “householding,” reduces the volume of duplicate information received at your household and helps to reduce our expenses.

If you would like to receive your own set of our disclosure documents, please contact us using the instructions set forth below. Similarly, if you share an address with another Greenhill stockholder and together both of you would like to receive only a single set of our disclosure documents, please contact us using the instructions set forth below.

If you are a Greenhill stockholder of record, you may contact us by writing to our Corporate Secretary at 1271 Avenue of the Americas, New York, New York 10020 or by calling our proxy solicitor, Georgeson LLC, at 866-391-7007. Eligible stockholders of record receiving multiple copies of this proxy statement can request householding by contacting us in the same manner. If a bank, broker or other nominee holds your shares, please contact your bank, broker or other nominee directly.

If you have any questions concerning the Merger, the Special Meeting or this proxy statement, would like additional copies of this proxy statement or need help voting your shares of Greenhill common stock, please contact our proxy solicitor:

Greenhill is asking holders of Greenhill common stock to approve and adopt the Merger Agreement and the transactions contemplated thereby, including the Merger. Holders of Greenhill common stock should read this proxy statement carefully and in its entirety, including the annexes, for more detailed information concerning the Merger Agreement and the Merger. A copy of the Merger Agreement is attached to this proxy statement as Annex A.

After careful consideration, the Board of Directors unanimously determined that the Merger Agreement, the Merger and the other transactions contemplated by the Merger Agreement are advisable, fair to and in the best interests of Greenhill and its stockholders and unanimously adopted and approved the Merger Agreement, the Merger and the other transactions contemplated by the Merger Agreement. See the section of this proxy statement entitled “The Merger—Recommendation of the Board of Directors and Reasons for the Merger” for a more detailed discussion of the Board of Directors’ recommendation.

The Board of Directors unanimously recommends a vote “FOR” the Merger Agreement Proposal.

Under Section 14A of the Exchange Act and the applicable SEC rules issued thereunder, Greenhill is required to submit a proposal to Greenhill stockholders to approve, on an advisory (nonbinding) basis, the compensation that may be paid or become payable to Greenhill’s named executive officers that is based on or otherwise relates to the Merger Agreement and the transactions contemplated by the Merger Agreement. This compensation is summarized in the section entitled “The Merger—Interests of Greenhill’s Executive Officers and Directors in the Merger.”

The Board of Directors encourages you to review carefully the named executive officer Merger-related compensation information disclosed in this proxy statement. Accordingly, Greenhill is asking you to approve the following resolution:

The vote on this Compensation Proposal is a vote separate and apart from the vote on the Merger Agreement Proposal. Accordingly, you may vote to approve the Merger Agreement Proposal and vote not to approve the Compensation Proposal and vice versa. The approval of the Compensation Proposal by holders of Greenhill common stock is not a condition to the completion of the Merger. Because the vote on the Compensation Proposal is advisory only, it will not be binding on Greenhill. Accordingly, if the Merger Agreement Proposal is approved and the Merger is completed, the compensation will be payable, subject only to the conditions applicable thereto, regardless of the outcome of the vote on this Compensation Proposal.

The Board of Directors unanimously recommends that you vote “FOR” the Compensation Proposal.

We are asking you to approve a proposal to adjourn the Special Meeting to a later date or dates if necessary or appropriate to solicit additional proxies if there are insufficient votes to adopt the Merger Agreement at the time of the Special Meeting or to ensure that any supplement or amendment to this proxy statement is timely provided to holders of Greenhill common stock. If Greenhill stockholders approve the Adjournment Proposal, we could adjourn the Special Meeting and any adjourned session of the Special Meeting and use the additional time to solicit additional proxies, including soliciting proxies from Greenhill stockholders that have previously returned properly executed proxies voting against the Merger Agreement Proposal. Among other things, approval of the Adjournment Proposal could mean that, even if we had received proxies representing a sufficient number of votes against the Merger Agreement Proposal such that the Merger Agreement Proposal would be defeated, we could adjourn the Special Meeting without a vote on the Merger Agreement Proposal and seek to convince the holders of those shares to change their votes to votes in favor of the Merger Agreement Proposal. Additionally, we may seek to adjourn the Special Meeting if a quorum is not present or otherwise at the discretion of the chair of the Special Meeting. The approval of the Adjournment Proposal by holders of Greenhill common stock is not a condition to the completion of the Merger.

The Board of Directors unanimously recommends that you vote “FOR” the Adjournment Proposal.

This discussion of the Merger is qualified in its entirety by reference to the Merger Agreement, which is attached to this proxy statement as Annex A and incorporated into this proxy statement by reference. You should carefully read and consider the entire Merger Agreement, which is the legal document that governs the Merger, because it contains important information about the Merger and how it affects you.

Greenhill is a leading independent investment bank that provides financial and strategic advice on significant domestic and cross-border mergers, acquisitions, restructurings, financings, capital raising and other transactions to a diverse client base, including corporations, partnerships, private equity sponsors, institutional investors, family offices and governments globally. Greenhill acts for clients located throughout the world from its offices in New York, Chicago, Frankfurt, Hong Kong, Houston, London, Madrid, Melbourne, Paris, San Francisco, Singapore, Stockholm, Sydney, Tokyo and Toronto. As of March 31, 2023, Greenhill had, on a consolidated basis, approximately $518.9 million in total assets, total stockholders’ equity of approximately $52.7 million and 18,310,176 shares of Greenhill common stock issued and outstanding.

Greenhill’s principal executive offices are located at 1271 Avenue of the Americas, New York, New York 10020, and its telephone number is (212) 389-1500.

Greenhill common stock is listed on the NYSE under the symbol “GHL.”

Mizuho Americas is the U.S. bank holding company and indirect wholly owned subsidiary of Mizuho Financial Group, Inc. (which we refer to as “Mizuho Financial Group”), a global financial services institution providing comprehensive financial and strategic services, including banking, securities, trust and asset management with assets of approximately $2 trillion. Mizuho Financial Group’s 60,000 employees worldwide offer comprehensive financial services to clients in 35 countries and 800 offices throughout the Americas, EMEA and Asia.

Mizuho Americas is a leading provider of corporate and investment banking services to clients in the U.S., Canada and Latin America. Its capabilities span investment and corporate banking, capital markets, equity and fixed income sales & trading, derivatives, FX, custody and research. Mizuho Americas employs 3,000 professionals across 15 offices within the Americas.

Mizuho Americas’ principal executive offices are located at 1271 Avenue of the Americas, New York, New York 10020, and its telephone number is (212) 209-9300.

Mizuho Financial Group common shares are listed on the Tokyo Stock Exchange under the symbol “MFG” and Mizuho Financial Group’s American Depositary Shares are listed on the NYSE under the symbol “MFG.”

Merger Sub is a wholly owned subsidiary of Mizuho Americas and was incorporated on May 17, 2023, solely for the purpose of engaging in the transactions contemplated by the Merger Agreement, and has not engaged in any activities other than in connection with or as contemplated by the Merger Agreement.

The principal executive offices of Merger Sub are located at 1271 Avenue of the Americas, New York, New York 10020 and its telephone number is (212) 209-9300.

On the terms and subject to the conditions of the Merger Agreement, and in accordance with the DGCL, at the Effective Time, Merger Sub will merge with and into Greenhill, the separate corporate existence of Merger Sub will cease and Greenhill will continue its corporate existence under the DGCL as the Surviving Corporation. As a result of the Merger, Greenhill will become a wholly owned subsidiary of Mizuho Americas, and Greenhill common stock will no longer be publicly traded and will be delisted from the NYSE. In addition, Greenhill common stock will be deregistered under the Exchange Act, and Greenhill will no longer file periodic or other reports with the SEC. If the Merger is completed, you will not own any shares of the capital stock of the Surviving Corporation.

The Effective Time will occur at such time as the certificate of merger with respect to the Merger has been duly filed with the Secretary of State of the State of Delaware or at such later date or time as may be mutually agreed by Greenhill and Mizuho Americas and specified in the certificate of merger in accordance with the DGCL.

If the Merger Agreement is not adopted by Greenhill stockholders, or if the Merger is not completed for any other reason:

At the Effective Time, by virtue of the Merger and without any action on the part of Greenhill, Mizuho Americas or Merger Sub, or the holders of any securities of Greenhill or Merger Sub, each share of Greenhill common stock (other than Canceled Shares and Dissenting Shares) issued and outstanding immediately prior to the Effective Time will be converted automatically into the right to receive the Merger Consideration of $15.00 in cash, without interest, subject to any required tax withholding.

After the Merger is completed, you will have the right to receive the Merger Consideration in respect of each share of Greenhill common stock that you own (other than any Canceled Shares and Dissenting Shares) immediately prior to the Effective Time (subject to any required tax withholding), but you will no longer have any rights as a Greenhill stockholder (except that Greenhill stockholders and beneficial owners who properly and validly demand appraisal in accordance with Section 262 of the DGCL will not be entitled to receive the Merger Consideration and instead will have a right to receive payment of the “fair value” of their shares as determined pursuant to an appraisal proceeding, as contemplated by the DGCL). For more information, please see the section of this proxy statement entitled “—Appraisal Rights.”

At the Effective Time, each award of RSUs that is outstanding as of immediately prior to the Effective Time will be converted into an unvested Mizuho Cash Award with respect to an amount in cash equal to the product obtained by multiplying (A) the Merger Consideration by (B) the number of shares of Greenhill common stock covered by such award of RSUs immediately prior to the Effective Time, which Mizuho Cash Award will otherwise be subject to the same terms and conditions applicable to such award of RSUs (including eligibility to vest in accordance with the vesting schedule set forth in the award agreement evidencing such award of RSUs

and any vesting acceleration or treatment upon termination of employment terms set forth in the applicable Greenhill stock plan or award agreement, to the extent applicable) as of immediately prior to the Effective Time. Any amounts relating to dividend equivalent rights, if any, granted with respect to such RSUs that are accrued but unpaid as of the Effective Time will carry over and will be paid if required by and in accordance with the terms and conditions as were applicable to such awards of RSUs immediately prior to the Effective Time,

At the Effective Time, each award of PSUs that is outstanding immediately prior to the Effective Time will become fully vested with respect to the number of shares of Greenhill common stock covered by such award of PSUs based on the target level of performance and will be converted into the right to receive an amount in cash equal to the product obtained by multiplying (A) the Merger Consideration by (B) the Applicable Number, paid within 10 business days following the Effective Time or such later date as required to avoid the imposition of taxes under Section 409A of the Code. Any amounts relating to dividend equivalent rights, if any, granted with respect to awards of PSUs that are accrued but unpaid as of the Effective Time will be paid within 10 business days following the Effective Time or at such later date required to avoid the imposition of taxes under Section 409A of the Code.

At the Effective Time, each Deferred Cash Award that is outstanding immediately prior to the Effective Time will be converted into a Mizuho Cash Award with respect to an equivalent amount in cash that has not yet been paid with respect to the Deferred Cash Award as of immediately prior to the Effective Time, which will otherwise be subject to the same terms and conditions applicable to such Deferred Cash Award (including eligibility to vest in accordance with the vesting schedule set forth in the award agreement evidencing such Deferred Cash Award and any vesting acceleration or treatment upon termination of employment terms set forth in the applicable Greenhill stock plan or award agreement, to the extent applicable) as of immediately prior to the Effective Time.

As part of Greenhill’s ongoing consideration and evaluation of its long-term strategic goals and plans, the Board of Directors and Greenhill’s management regularly review, consider and assess Greenhill’s performance, strategy, competitive position, opportunities and prospects in light of the then-current business, economic and regulatory environments, as well as overall industry conditions and the opportunities and challenges facing participants in the investment banking industry, and specifically independent investment banking firms with a focus on advisory services, in each case with the goal of enhancing value for Greenhill’s stockholders, and delivering the best possible services to Greenhill’s clients. These reviews have included consideration, from time to time, of potential opportunities for business combinations, acquisitions and other financial and strategic alternatives, accompanied by occasional conversations between senior executives of Greenhill and their counterparts at other companies in the financial services industry regarding such potential transactions and opportunities.

During July of 2022, a representative of Houlihan Lokey contacted Scott L. Bok, Chairman and Chief Executive Officer of Greenhill and discussed developments in the investment banking industry and M&A market activity. The representative of Houlihan Lokey proposed introducing Mr. Bok to a representative of Mizuho Financial Group (which, together with its subsidiaries, including Mizuho Americas, we refer to as “Mizuho”) who he indicated may have an interest in partnering with or acquiring a merger and acquisition advisory business with a significant presence in the United States. Mr. Bok declined to meet with Mizuho at that time, and indicated that Greenhill was focused on executing its stand-alone plan as an independent company. Mr. Bok subsequently informed the Board of Directors at its next regularly scheduled meeting of the conversation with the Houlihan Lokey representative.

During Greenhill’s regularly scheduled board meeting on January 31, 2023, Greenhill management discussed with the Board of Directors the company’s recent performance, outlook and near- and long-term strategic objectives, as well as the company’s plans for refinancing the $271.9 million term loan which would mature in April 2024. In an executive session at that meeting, the Board of Directors also discussed the reduced level of M&A activity in the U.S. and Europe in 2022 and early 2023 and the various macroeconomic factors impacting

M&A, including rapidly rising interest rates to combat higher inflation, the Russian invasion of Ukraine, the negative performance and volatility in the equity markets, less liquid and more expensive credit markets, and a more challenging regulatory environment. That discussion also included a review of recent developments and trends in the investment banking sector, including with respect to intense competition with large and mid-size full service investment banking firms and other independent advisory-focused investment banking firms for what were a reduced number of transaction advisory opportunities, and recent consolidation in the investment banking industry, as evidenced by the pending acquisition of independent investment banking firm Cowen Inc. by TD Bank Group, and the potential benefits of scale and a broader product offering. The discussion also included an evaluation of how such developments and trends could affect the overall landscape in the investment banking sector and the potential benefits of combining with a larger financial institution if the right opportunity were to arise. As part of this discussion Mr. Bok reviewed with the Board of Directors his discussions with various industry participants over the course of the firm’s history and noted that Company A, a global financial institution, had recently contacted him to set up an initial meeting focused on its interest in exploring an acquisition of Greenhill.

At a meeting of the Board of Directors on March 8, 2023 scheduled for the purpose of reviewing and approving the filing of Greenhill’s annual proxy statement, Mr. Bok updated the Board of Directors that Company A had informed him on February 28, as a follow up to its initial meeting with him, that due to other strategic initiatives Company A would not be able to pursue a transaction at this time. Mr. Bok and the Board of Directors discussed that, while the initial approach from Company A had not led to a proposal, the discussions had been valuable in highlighting the potential benefits of a transaction between Greenhill and a larger global financial institution that had lending, financing and investment banking capabilities but lacked a significant advisory business. The Board of Directors concluded that it should remain focused on executing Greenhill’s stand-alone plan but also be open to potential strategic opportunities that may arise.

On March 23, 2023, Mr. Bok reached out to the Houlihan Lokey representative who had previously contacted him regarding arranging an introduction to Mizuho and indicated that he would be open to an initial conversation. Thereafter, Houlihan Lokey arranged for an introductory meeting between Mr. Bok and Jerry Rizzieri, President and CEO of Mizuho Securities USA. Houlihan Lokey provided discussion materials to Mizuho in advance of the introductory meeting, which included preliminary valuation information for Greenhill based on publicly available information.

On April 12, 2023, Mr. Bok and Mr. Rizzieri had the first of several informal preliminary discussions regarding market conditions and the broader industry landscape, including recent industry trends, and discussed their respective businesses. During these conversations, Mr. Rizzieri expressed Mizuho’s interest in accelerating its investment banking growth strategy in the United States and other prominent markets, potentially through the acquisition of an independent investment advisory firm like Greenhill.

Mr. Bok and Mr. Rizzieri again met on April 20, 2023. Mr. Bok presented information in relation to Greenhill’s business, and the parties discussed the benefits and value that could potentially be generated in a strategic transaction between Mizuho and Greenhill by leveraging each other’s complementary capabilities through combining the strength of Greenhill’s M&A and restructuring advisory business with the wide range of financing, capital markets and other products offered by Mizuho. As the discussion continued it became clear that Mizuho had a strong interest in exploring a potential transaction with Greenhill. Mr. Rizzieri expressed that Mizuho viewed the retention of the Greenhill brand, global network, leadership and investment banking team as being integral to the value of a transaction between Mizuho and Greenhill. At the April 20 meeting, Mr. Bok also discussed his view that the recent trading price of Greenhill common stock (which, on April 19, the trading day prior to the April 20 meeting, closed at $7.97 per share) did not reflect Greenhill’s intrinsic value, and that the trading price had been adversely affected by recent extrinsic events that had impacted market volatility as well as resulted in reduced M&A activity. He noted that prior to the global COVID-19 pandemic and then again prior to Russia’s invasion of Ukraine, Greenhill’s common stock had traded closer to $20.00 per share. Mr. Rizzieri did not comment on the views expressed by Mr. Bok regarding Greenhill’s trading price.

Later in the day on April 20 following the conclusion of his meeting with Mr. Rizzieri, Mr. Bok informed the Board of Directors of his preliminary discussions with Mr. Rizzieri regarding a potential strategic transaction between Greenhill and Mizuho. All members of the Board of Directors expressed their support for Mr. Bok to continue his conversations with Mr. Rizzieri.

On April 26, 2023, Mr. Bok met with Mr. Rizzieri and Shuji Matsuura, Chairman and CEO of Mizuho Americas, to further discuss the possibility of a business combination and Mr. Bok, Mr. Rizzieri and Mr. Matsuura spent time discussing their respective businesses and the strategic rationale for an acquisition by Mizuho of Greenhill.

Mr. Bok and Mr. Rizzieri, along with members of their respective management teams, met again on April 27, 2023. At that meeting Mr. Bok shared a valuation matrix with Mr. Rizzieri showing a range of transaction values from $13.00 to $21.00 per share of Greenhill common stock and proposed to Mr. Rizzieri that a business combination transaction between Mizuho and Greenhill should value Greenhill at the mid-point of $17.00 per share or higher. The proposed $17.00 per share transaction price reflected a 141.5% premium to Greenhill’s closing stock price of $7.04 on April 27, 2023. Mr. Bok also discussed with Mr. Rizzieri the publicly disclosed fact that, under the terms of Greenhill’s equity plans, outstanding restricted stock units held by Greenhill employees, which represent a significant portion of their compensation, would convert at the closing of a transaction into cash awards at the deal price and continue to time vest in accordance with their terms post-closing, which could provide a significant retentive value to Mizuho. Mr. Bok also discussed that a transaction would require repayment by Mizuho at closing of Greenhill’s outstanding $270.1 million term loan pursuant to its terms. Mr. Rizzieri noted his continued strong interest in a transaction, but did not comment on the proposed transaction price.

On May 2, 2023, the Board of Directors held a regularly scheduled meeting. At the meeting, Mr. Bok provided an update to the Board of Directors on his discussions with Mr. Rizzieri, noting that Mizuho had expressed a strong interest in a business combination transaction with Greenhill and that Mr. Bok had proposed a price of $17.00 per share in cash. Mr. Bok informed the Board of Directors that he did not expect Mizuho to agree to the $17.00 price but that he believed that he would be able to negotiate a price with Mizuho that represented a very significant premium to Greenhill’s current trading price and that would provide substantial value for Greenhill’s stockholders. Mr. Bok also discussed the compelling strategic rationale for a transaction and noted that Mizuho had expressed its desire to retain the Greenhill brand, leadership and investment banking teams. The Board of Directors discussed the potential benefits and risks of pursuing a strategic business combination with Mizuho. The Board of Directors also discussed that while certain other parties had in the past expressed informal interest in a potential strategic transaction involving Greenhill, such inquiries had not led to any actionable proposals for a strategic transaction and discussed the risk both to Greenhill’s business and the discussions with Mizuho that could result from a leak or market rumors if Greenhill were to conduct outreach to other parties at this time. The Board of Directors determined that it was advisable for Greenhill and its representatives to continue its discussions with Mizuho to determine whether Greenhill could negotiate a transaction with a price and other terms that would be in the best interest of Greenhill stockholders.

At the direction of the Board of Directors, over the next few days, representatives of Greenhill discussed and negotiated the key terms of a potential strategic transaction with representatives of Mizuho, which were to be reflected in a non-binding term sheet, and Greenhill provided limited due diligence to Mizuho. As part of these discussions, on May 4, 2023, Mr. Bok and Mr. Rizzieri had a series of negotiations regarding the proposed price per share of a potential all-cash transaction between Greenhill and Mizuho. Following Mr. Rizzieri’s initial proposal of a $13.00 per share transaction price, Mr. Bok countered with a price of $15.50 and the pricing negotiations became focused on a price between $14.50 and $15.50 before narrowing to a range of $14.50 and $15.00. Later that evening after their last pricing discussion, Mr. Rizzieri communicated to Mr. Bok that Mizuho would be willing to acquire Greenhill for a price of $15.00 per common share, which reflected a 120.9% premium to Greenhill’s closing stock price of $6.79 on May 4, 2023, and that this represented the highest value that Mizuho was willing to offer.

As part of the negotiations on key transaction terms, Mr. Bok and Mr. Rizzieri agreed that in any business combination between the two companies, Mizuho would commit to maintain the Greenhill brand and Greenhill would operate as Mizuho’s global M&A and advisory group. Mr. Bok emphasized the importance to Greenhill of certainty of closing with limited conditionality as well as the importance of maintaining confidentiality throughout any transaction process due to the risk to Greenhill’s business, and specifically employee retention, that could result from market rumors or leaks. Mr. Rizzieri was focused on employee retention in connection with a transaction and discussed that Mizuho would require Mr. Bok to enter into an offer letter as a condition to signing and Mr. Bok and Mr. Rizzieri discussed the terms on which Mizuho would employ Mr. Bok as well as other personnel matters. Mr. Rizzieri agreed that Mizuho would not require any other employees to enter into agreements prior to signing a definitive transaction agreement because of the significant retentive value of the

Greenhill restricted stock units that would be converted into cash at the deal price and continue to time vest following the closing, Mizuho’s confidence that the combined Mizuho/Greenhill platform should provide enhanced opportunities for revenue generation and related higher compensation for all key employees as well as the increased risk of a leak associated with the delay in signing a merger agreement that would result from negotiating agreements with individual employees. Mr. Rizzieri indicated that Mizuho would be willing to move quickly to a signing and conduct a targeted due diligence review but would require that Greenhill agree to exclusive negotiations for a limited period and also that in connection with entry into a transaction Mizuho would require Mr. Bok to enter into a voting agreement in his capacity as a stockholder but would not require a voting agreement from any other stockholders.

On May 5, 2023, the Board of Directors held a special meeting. At the meeting, Mr. Bok provided an update on his discussions and negotiations with Mr. Rizzieri, including the key terms that were to be memorialized in a non-binding term sheet, and the Board of Directors engaged in further discussions regarding the benefits of the proposed transaction with Mizuho relative to Greenhill’s available alternatives, including its stand-alone plan and the benefits, risks and uncertainties associated with the stand-alone plan in the current economic environment, as compared to the potential benefits, risks and uncertainties of a potential transaction with Mizuho. The Board of Directors noted that the proposed merger consideration of $15.00 in cash per share reflected a very substantial premium that exceeded Greenhill’s likely near term value as a standalone company, including taking into account Greenhill’s potential for, and risks to, future growth. The Board of Directors and management also reviewed and discussed whether to proactively contact other potential counterparties as well as Mizuho’s requirement that Greenhill enter into an agreement to exclusively negotiate with Mizuho for approximately 30 days. The Board of Directors and management discussed its view that it was unlikely, based on its extensive knowledge of the industry (including Mr. Bok’s discussions with various industry participants over the course of the firm’s history), that a third party would be willing to enter into a transaction with Greenhill on more attractive terms than the Mizuho proposal at that time as well as the significant risks to Greenhill and its business posed by contacting other potential counterparties, including concerns that market leaks and rumors regarding a potential transaction would disrupt Greenhill’s business relationships and risk employee attrition, as well as lead to turnover in its stockholder base and potential stock price volatility, and could put the highly attractive Mizuho transaction at risk. The Board of Directors discussed the importance of moving to execute a transaction with Mizuho quickly to limit the risk of leaks and the risk of losing the highly attractive offer that was in hand, the importance of entering into a transaction that offered substantial certainty of closing and the relatively short duration of the exclusivity agreement, which the directors believed would incentivize Mizuho to sign a transaction within that period of time. At the conclusion of the meeting, after careful review and discussion by the Board of Directors, the Board of Directors determined that the proposed transaction with Mizuho offered greater benefits to Greenhill and its stockholders as compared to Greenhill’s available alternatives, and authorized Greenhill management to move forward with exclusive negotiations with Mizuho and to negotiate definitive documentation with Mizuho on terms that would maximize closing certainty, which documentation would remain subject to final board approval. Greenhill management also discussed with the Board of Directors its proposal to retain Houlihan Lokey as financial advisor in connection with the potential transaction. Following a discussion among the Board of Directors and management of Houlihan Lokey’s experience in the industry, its role in introducing Greenhill to Mizuho, Houlihan Lokey’s prior contacts with Mizuho, and the Board of Directors’ desire to limit the risk of leaks in the financial advisory industry, the Board of Directors authorized management to formally engage Houlihan Lokey at the appropriate time.

Following the May 5, 2023 meeting of the Board of Directors, members of Greenhill management engaged in further discussions with members of Mizuho management to finalize the transaction terms to be included in a non-binding term sheet, and continued their prior discussions regarding their respective businesses, including personnel matters, and the cultural and strategic fit of the two companies. On May 5, 2023, Mr. Rizzieri provided to Mr. Bok drafts of a mutual non-disclosure agreement and an exclusivity agreement. On May 6, 2023, Mr. Rizzieri provided to Mr. Bok a non-binding term sheet for the potential transaction between Greenhill and Mizuho that reflected the terms that had been negotiated by the Greenhill and Mizuho representatives over the preceding days. Also on May 6, 2023, Mr. Rizzieri sent Mr. Bok a non-binding term sheet setting forth the proposed terms that had been discussed for Mizuho’s offer of employment to Mr. Bok, which Mizuho was requiring be memorialized in an offer letter to be signed contemporaneously with the merger agreement. Over the course of the next few days, Wachtell, Lipton, Rosen & Katz (which we refer to as “Wachtell Lipton”), legal advisor to Greenhill, assisted Greenhill with Greenhill’s evaluation of the mutual non-disclosure agreement, the exclusivity agreement, the transaction term sheet and the Bok term sheet.

On May 9, 2023, Greenhill and Mizuho entered into the mutual non-disclosure agreement to facilitate further discussions between the parties, which contained a customary standstill provision that would automatically terminate upon the entry by Greenhill into a binding definitive written agreement for the acquisition of Greenhill by a third party, and the exclusivity agreement, which provided that the parties would negotiate on an exclusive basis until June 6, 2023.

Following the execution of the mutual non-disclosure agreement and continuing until the merger agreement was executed, Mizuho performed due diligence reviews, including through documents provided in an electronic data room and through a series of virtual and telephonic due diligence meetings covering relevant due diligence matters and the integration of the companies’ businesses if a strategic transaction between Greenhill and Mizuho were agreed upon. Also during this period, Wachtell Lipton assisted Greenhill with Greenhill’s evaluation of the potential transaction and Mr. Bok kept the Board of Directors apprised of significant developments in Greenhill’s negotiations with Mizuho.

On May 11, 2023, Paul, Weiss, Rifkind, Wharton & Garrison LLP (which we refer to as “Paul Weiss”) provided an initial draft of the offer letter for Mr. Bok’s employment with Mizuho to Wachtell Lipton, and on May 12, 2023, Paul Weiss provided initial drafts of the merger agreement and voting agreement to Wachtell Lipton. Thereafter and continuing until the merger agreement was executed, the parties and their counsel negotiated the terms of the transaction documents, and Wachtell Lipton and Paul Weiss exchanged several revised versions of the drafts of the merger agreement, voting agreement and offer letter, reflecting discussions between the parties regarding transaction terms. During the course of these negotiations, areas of discussion and negotiation between the parties included, among other things, the representations and warranties to be made by the parties, Mizuho’s obligations with respect to obtaining required regulatory approvals for the potential transaction, the scope of the restrictions applicable to actions taken by Greenhill during the period between the signing of the merger agreement and the consummation of the merger, Mizuho’s agreement to refinance Greenhill’s term loan if the transaction has not closed by a specified date, the conditions to completion of the merger, the termination provisions and the termination fees payable by Greenhill or Mizuho under certain circumstances, and the provisions regarding Greenhill’s equity awards, employee benefit plans and other compensation matters.

On May 18, 2023, Greenhill engaged Houlihan Lokey to act as financial advisor to the Board of Directors in connection with a potential business combination transaction.

On May 21, 2023, the Board of Directors held a special meeting to consider the negotiated terms of the proposed acquisition of Greenhill by Mizuho and entry into the merger agreement by Greenhill. A representative of Wachtell Lipton reviewed with the Greenhill directors the proposed final terms of the merger agreement, as well as the proposed final terms of the other transaction documents to be entered into in connection with the merger agreement. A representative of Wachtell Lipton also reviewed the directors’ fiduciary duties in connection with the proposed transaction, and described the resolutions the Greenhill directors would be asked to adopt if they were to approve the transaction. A representative of Houlihan Lokey reviewed with the Board of Directors certain matters relating to Houlihan Lokey’s prior engagements with Mizuho, as described further in the section entitled “—Opinion of Houlihan Lokey Capital, Inc.” A representative of Houlihan Lokey also reviewed Houlihan Lokey’s financial analyses with respect to the proposed transaction and rendered Houlihan Lokey’s oral opinion, confirmed by delivery of a written opinion dated May 21, 2023, to the Board of Directors to the effect that, as of the date of such opinion, and based upon and subject to the limitations, qualifications, assumptions and other matters considered in connection with the preparation of such opinion, the merger consideration to be received by the Greenhill stockholders pursuant to the merger agreement was fair, from a financial point of view, to such stockholders. At the conclusion of the meeting, after careful review and discussion by the Board of Directors, including consideration of the factors described below under “—Recommendation of the Board of Directors and Reasons for the Merger,” the Board of Directors unanimously determined that the merger agreement and the voting agreement and the transactions contemplated thereby, including the merger, were advisable and in the best interests of Greenhill and its stockholders and unanimously adopted and approved the merger agreement, the voting agreement, the merger, and the other transactions contemplated thereby.

Following the Board of Directors’ approval, on the morning of May 22, 2023, Greenhill and Mizuho executed the merger agreement and announced the transaction before the opening of the financial markets in New York in a press release jointly issued by Greenhill and Mizuho.

The Board of Directors has unanimously: (a) determined that the Merger Agreement and the transactions contemplated thereby, including the Merger, are advisable, fair to and in the best interests of Greenhill and its stockholders; (b) approved and adopted the Merger Agreement and the transactions contemplated thereby, including the Merger; (c) recommended that Greenhill stockholders adopt the Merger Agreement; and (d) directed that the adoption of the Merger Agreement be submitted for consideration by Greenhill stockholders at the Special Meeting.

The Board of Directors unanimously recommends that you vote: (1) “FOR” the Merger Agreement Proposal; (2) “FOR” the Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

In reaching its decision to approve and adopt the Merger Agreement, declare the Merger Agreement and the transactions contemplated by the Merger Agreement, including the Merger, to be advisable, fair to and in the best interests of Greenhill and its stockholders, and recommend that Greenhill stockholders adopt the Merger Agreement, the Board of Directors consulted with Greenhill’s senior management team, as well as our financial and legal advisors, and considered a number of factors, including the following factors that the Board of Directors viewed as supporting its decision:

The Board of Directors also considered a variety of risk and other potential negative factors in its consideration of the Merger Agreement and the Merger, including the following potentially negative factors:

The foregoing discussion of the factors considered by the Board of Directors is not intended to be exhaustive, but rather includes the material factors considered by the Board of Directors. In reaching its decision to approve the Merger Agreement, declare the Merger Agreement and the transactions contemplated by the Merger Agreement, including the Merger, to be advisable, fair to and in the best interests of Greenhill and its stockholders, and recommend adoption of the Merger Agreement by our stockholders, the Board of Directors did

not quantify, rank or otherwise assign any relative weights to, and did not make specific assessments of, the factors considered, and individual directors may have given different weights to different factors. The Board of Directors did not reach any specific conclusion with respect to any of the factors or reasons considered, but determined, in its business judgment, that, in the aggregate, the potential benefits considered outweighed the potential risks or possible negative consequences of approving the Merger Agreement, the Merger and the other transactions contemplated by the Merger Agreement.

The above factors are not presented in any order of priority. The explanation of the factors and reasoning set forth above contain forward-looking statements and should be read in conjunction with the section of this proxy statement entitled “Forward-Looking Statements.”

On May 21, 2023, Houlihan Lokey orally rendered its opinion to the Board of Directors (which was subsequently confirmed in writing by delivery of Houlihan Lokey’s written opinion addressed to the Board of Directors dated May 21, 2023) as to, as of such date, the fairness, from a financial point of view, to the holders of Greenhill common stock of the Merger Consideration to be received by such holders in the Merger pursuant to the Merger Agreement.

Houlihan Lokey’s opinion was furnished for the use of the Board of Directors (in its capacity as such), and only addressed the fairness, from a financial point of view, to the holders of Greenhill common stock of the Merger Consideration to be received by such holders in the Merger pursuant to the Merger Agreement and did not address any other aspect or implication of the Merger or any other agreement, arrangement or understanding. The summary of Houlihan Lokey’s opinion in this proxy statement is qualified in its entirety by reference to the full text of its written opinion, which is attached as Annex C to this proxy statement and describes the procedures followed, assumptions made, qualifications and limitations on the review undertaken and other matters considered by Houlihan Lokey in connection with the preparation of its opinion. However, neither Houlihan Lokey’s opinion nor the summary of its opinion and the related analyses set forth in this proxy statement are intended to be, and do not constitute, advice or a recommendation to the Board of Directors, any security holder or any other person as to how to act or vote with respect to any matter relating to the Merger or otherwise.

In connection with its opinion, Houlihan Lokey made such reviews, analyses and inquiries as it deemed necessary and appropriate under the circumstances. Among other things, Houlihan Lokey:

Houlihan Lokey relied upon and assumed, without independent verification, the accuracy and completeness of all data, material and other information furnished, or otherwise made available, to it, discussed with or reviewed by it, or publicly available, and did not assume any responsibility with respect to such data, material and other information. In addition, management of Greenhill advised Houlihan Lokey and, at Greenhill’s direction, Houlihan Lokey assumed that (i) the Management Projections were reasonably prepared in good faith on bases reflecting the best currently available estimates and judgments of such management as to the future financial results and condition of Greenhill, (ii) the NOLs were reasonably prepared in good faith on bases reflecting the best currently available estimates and judgments of such management as to the amount of such NOLs, and (iii) the Estimated NOL Tax Savings were reasonably prepared in good faith on bases reflecting the best currently available estimates and judgments of such management as to Greenhill’s ability to utilize those NOLs to achieve future tax savings. At Greenhill’s direction, Houlihan Lokey assumed that the Management Projections, the NOLs and the Estimated NOL Tax Savings provided a reasonable basis on which to evaluate Greenhill and the Merger, and Houlihan Lokey, at Greenhill’s direction, used and relied upon the Management Projections, the NOLs and the Estimated NOL Tax Savings for purposes of its analyses and opinion. Houlihan Lokey expressed no view or opinion with respect to the Management Projections, the NOLs, the Estimated NOL Tax Savings or the respective assumptions on which they were based. In reaching its conclusions under the opinion, with Greenhill’s consent, Houlihan Lokey did not rely upon a review of the publicly available financial terms of other transactions, because Houlihan Lokey did not identify a sufficient number of relevant transactions in which Houlihan Lokey deemed the acquired companies to be sufficiently similar to Greenhill. Houlihan Lokey relied upon and assumed, without independent verification, that there had been no change in the business, assets, liabilities, financial condition, results of operations, cash flows or prospects of Greenhill since the respective dates of the most recent financial statements and other information, financial or otherwise, provided to Houlihan Lokey that would be material to its analyses or opinion, and that there was no information or any facts that would make any of the information reviewed by Houlihan Lokey incomplete or misleading.

Houlihan Lokey relied upon and assumed, without independent verification, that (a) the representations and warranties of all parties to the Merger Agreement and all other related documents and instruments referred to therein were true and correct, (b) each party to the Merger Agreement and such other related documents and instruments would fully and timely perform all of the covenants and agreements required to be performed by such party, (c) all conditions to the consummation of the Merger would be satisfied without waiver thereof, and (d) the Merger would be consummated in a timely manner in accordance with the terms described in the Merger Agreement and such other related documents and instruments, without any amendments or modifications thereto. Houlihan Lokey relied upon and assumed, without independent verification, that (i) the Merger would be consummated in a manner that complies in all respects with all applicable foreign, federal, state and local statutes, rules and regulations, and (ii) all governmental, regulatory, and other consents and approvals necessary for the consummation of the Merger would be obtained and that no delay, limitations, restrictions or conditions would be imposed or amendments, modifications or waivers made that would have an effect on Greenhill or the Merger that would be material to its analyses or opinion. In addition, Houlihan Lokey relied upon and assumed, without independent verification, that the final form of the Merger Agreement would not differ in any respect from the draft of the Merger Agreement identified above.

Furthermore, in connection with its opinion, Houlihan Lokey was not requested to, and did not, make any physical inspection or independent appraisal or evaluation of any of the assets, properties or liabilities (fixed, contingent, derivative, off-balance-sheet or otherwise) of Greenhill or any other party, nor was Houlihan Lokey provided with any such appraisal or evaluation. Houlihan Lokey did not estimate, and expressed no opinion regarding, the liquidation value of any entity or business. Houlihan Lokey did not undertake any independent analysis of any potential or actual litigation, regulatory action, possible unasserted claims or other contingent liabilities to which Greenhill was or may have been a party or was or may have been subject, or of any governmental investigation of any possible unasserted claims or other contingent liabilities to which Greenhill was or may have been a party or was or may have been subject.

Houlihan Lokey was not requested to, and did not, (a) solicit any indications of interest from third parties with respect to the Merger, the securities, assets, businesses or operations of Greenhill or any other party, or any alternatives to the Merger, (b) negotiate the terms of the Merger, or (c) advise the Board of Directors or any other party with respect to alternatives to the Merger. Houlihan Lokey expressed no view or opinion as to any such matters, including the terms that might have been obtained if any of the foregoing had been undertaken. Houlihan Lokey’s opinion was necessarily based on financial, economic, market and other conditions as in effect

on, and the information made available to Houlihan Lokey as of, the date of its opinion. Houlihan Lokey did not undertake, and is under no obligation, to update, revise, reaffirm or withdraw its opinion, or otherwise comment on or consider events occurring or coming to its attention after the date of its opinion. Houlihan Lokey did not express any view or opinion as to the price or range of prices at which shares of Greenhill common stock could be purchased or sold, or otherwise be transferable, at any time.

Houlihan Lokey’s opinion was furnished for the use of the Board of Directors (in its capacity as such) in connection with its evaluation of the Merger and may not be used for any other purpose without Houlihan Lokey’s prior written consent. Houlihan Lokey’s opinion was not intended to be, and does not constitute, a recommendation to the Board of Directors, Greenhill, any security holder or any other party as to how to act or vote with respect to any matter relating to the Merger or otherwise.

Houlihan Lokey was not requested to opine as to, and its opinion did not express an opinion as to or otherwise address, among other things: (i) the underlying business decision of the Board of Directors, Greenhill, its security holders or any other party to proceed with or effect the Merger, (ii) the terms of any arrangements, understandings, agreements or documents related to, or the form, structure or any other portion or aspect of, the Merger or otherwise (other than the Merger Consideration to the extent expressly specified in its opinion), including, without limitation, the Voting Agreement, (iii) the fairness of any portion or aspect of the Merger to the holders of any class of securities, creditors or other constituencies of Greenhill, or to any other party, except if and only to the extent expressly set forth in the last sentence of its opinion, (iv) the relative merits of the Merger as compared to any alternative business strategies or transactions that might have been available for Greenhill or any other party, (v) the fairness of any portion or aspect of the Merger to any one class or group of Greenhill’s or any other party’s security holders or other constituents vis-à-vis any other class or group of Greenhill’s or such other party’s security holders or other constituents (including, without limitation, the allocation of any consideration amongst or within such classes or groups of security holders or other constituents), (vi) whether or not Greenhill, Mizuho Americas, their respective security holders or any other party is receiving or paying reasonably equivalent value in the Merger, (vii) the solvency, creditworthiness or fair value of Greenhill, Mizuho Americas or any other participant in the Merger, or any of their respective assets, under any applicable law relating to bankruptcy, insolvency, fraudulent conveyance or similar matters, or (viii) the fairness, financial or otherwise, of the amount, nature or any other aspect of any compensation to or consideration payable to or received by any officers, directors or employees of any party to the Merger, any class of such persons or any other party, relative to the Merger Consideration or otherwise. Houlihan Lokey did not express any opinion, counsel or interpretation regarding matters that require legal, regulatory, accounting, insurance, tax or other similar professional advice. Houlihan Lokey assumed that such opinions, counsel or interpretations had been or would be obtained from the appropriate professional sources. Furthermore, Houlihan Lokey relied, with the consent of the Board of Directors, on the assessments by the Board of Directors, Greenhill, Mizuho Americas and their respective advisors, as to all legal, regulatory, accounting, insurance, tax and other similar matters with respect to Greenhill, the Merger or otherwise.

In performing its analyses, Houlihan Lokey considered general business, economic, industry and market conditions, financial and otherwise, and other matters as they existed on, and could be evaluated as of, the date of its opinion. No company used in Houlihan Lokey’s analyses for comparative purposes is identical to Greenhill and an evaluation of the results of those analyses is not entirely mathematical. The estimates contained in the Management Projections and the implied reference range values indicated by Houlihan Lokey’s analyses are not necessarily indicative of actual values or predictive of future results or values, which may be significantly more or less favorable than those suggested by the analyses. In addition, any analyses relating to the value of assets, businesses or securities do not purport to be appraisals or to reflect the prices at which businesses or securities actually may be sold, which may depend on a variety of factors, many of which are beyond the control of Greenhill. Much of the information used in, and accordingly the results of, Houlihan Lokey’s analyses are inherently subject to substantial uncertainty.

Houlihan Lokey’s opinion was only one of many factors considered by the Board of Directors in evaluating the proposed Merger. Neither Houlihan Lokey’s opinion nor its analyses were determinative of the Merger Consideration or of the views of the Board of Directors or management with respect to the Merger or the Merger Consideration. The type and amount of consideration payable in the Merger were determined through negotiation between Greenhill and Mizuho Americas, and the decision to enter into the Merger Agreement was solely that of the Board of Directors.

In preparing its opinion to the Board of Directors, Houlihan Lokey performed a variety of analyses, including those described below. The summary of Houlihan Lokey’s analyses is not a complete description of the analyses underlying Houlihan Lokey’s opinion. The preparation of such an opinion is a complex process involving various quantitative and qualitative judgments and determinations with respect to the financial, comparative and other analytical methods employed and the adaptation and application of these methods to the unique facts and circumstances presented. As a consequence, neither Houlihan Lokey’s opinion nor its underlying analyses is readily susceptible to summary description. Houlihan Lokey arrived at its opinion based on the results of all analyses undertaken by it and assessed as a whole and did not draw, in isolation, conclusions from or with regard to any individual analysis, methodology or factor. While the results of each analysis were taken into account in reaching Houlihan Lokey’s overall conclusion with respect to fairness, Houlihan Lokey did not make separate or quantifiable judgments regarding individual analyses. Accordingly, Houlihan Lokey believes that its analyses and the following summary must be considered as a whole and that selecting portions of its analyses, methodologies and factors, without considering all analyses, methodologies and factors, could create a misleading or incomplete view of the processes underlying Houlihan Lokey’s analyses and opinion.

The following is a summary of the material financial analyses performed by Houlihan Lokey in connection with the preparation of its opinion and reviewed with the Board of Directors on May 21, 2023. The order of the analyses does not represent relative importance or weight given to those analyses by Houlihan Lokey. The analyses summarized below include information presented in tabular format. The tables alone do not constitute a complete description of the analyses. Considering the data in the tables below without considering the full narrative description of the analyses, as well as the methodologies underlying, and the assumptions, qualifications and limitations affecting, each analysis, could create a misleading or incomplete view of Houlihan Lokey’s analyses.

For purposes of its analyses, Houlihan Lokey reviewed a number of financial metrics, including the following:

Unless the context indicates otherwise, equity values used in the selected companies analysis described below were calculated using the closing prices of the common stock of the selected companies listed below as of May 19, 2023. The estimates of the future financial performance of Greenhill relied upon for the financial analyses described below were based on the Management Projections, and estimates of the future financial performance of the selected companies listed below were based on publicly available research analyst estimates for those companies.

Selected Companies Analysis. Houlihan Lokey reviewed certain financial data for selected companies with publicly traded equity securities that Houlihan Lokey deemed relevant.

The financial data reviewed included:

The selected companies and resulting low, high, median and mean financial data included the following:

Taking into account the results of the selected companies analysis, Houlihan Lokey applied selected multiple ranges of 8.0x to 10.0x FY 2020-FY 2022 Avg. Adjusted EBITDA and 6.0x to 8.0x FY 2024E Adjusted EBITDA to corresponding financial data for Greenhill. The selected companies analysis indicated implied value reference ranges per share of Greenhill common stock of $9.32 to $13.66 based on FY 2020-FY 2022 Avg. Adjusted EBITDA and $8.64 to $14.21 based on FY 2024E Adjusted EBITDA, in each case as compared to the Merger Consideration of $15.00 per share of Greenhill common stock.

Discounted Cash Flow Analysis. Houlihan Lokey performed a discounted cash flow analysis of Greenhill by calculating the estimated net present value of the projected unlevered, after-tax free cash flows of Greenhill based on the Management Projections. Houlihan Lokey calculated terminal values for Greenhill by applying a range of perpetuity growth rates of 2.0% to 3.0% to Greenhill’s normalized estimated 2027 unlevered free cash flows. The net present values of Greenhill’s projected future cash flows and implied terminal values were then calculated using discount rates ranging from 12.0% to 15.0%. The discounted cash flow analysis indicated an implied value reference range per share of Greenhill common stock of $9.31 to $15.38, as compared to the Merger Consideration of $15.00 per share of Greenhill common stock.

Houlihan Lokey was engaged by Greenhill to act as its financial advisor in connection with a possible merger, consolidation, business combination, sale or other similar transaction. Greenhill engaged Houlihan Lokey based on Houlihan Lokey’s experience and reputation. Houlihan Lokey is regularly engaged to provide financial advisory services in connection with mergers and acquisitions, financings and financial restructurings. Pursuant to its engagement by Greenhill, Houlihan Lokey became entitled to a transaction fee of $5 million, of which $1 million became payable to Houlihan Lokey upon the rendering of its opinion to the Board and the remainder of which is contingent upon the consummation of the Merger. Greenhill has also agreed to reimburse Houlihan Lokey for certain expenses and to indemnify Houlihan Lokey, its affiliates and certain related parties against certain liabilities and expenses, including certain liabilities under the federal securities laws, arising out of or related to Houlihan Lokey’s engagement.

In the ordinary course of business, certain of Houlihan Lokey’s employees and affiliates, as well as investment funds in which they may have financial interests or with which they may co-invest, may acquire, hold or sell, long or short positions, or trade, in debt, equity, and other securities and financial instruments (including loans and other obligations) of, or investments in, Greenhill, Mizuho Americas or any other party that may be involved in the Merger and their respective affiliates or security holders or any currency or commodity that may be involved in the Merger.

Houlihan Lokey and certain of its affiliates have in the past provided investment banking, financial advisory and/or other financial or consulting services to Mizuho Securities USA LLC (which we refer to as “Mizuho USA”), an affiliate of Mizuho, for which Houlihan Lokey and its affiliates have received aggregate compensation of approximately $1.5 million during the past two years, including for having acted as financial advisor to Mizuho USA in connection with its acquisition of Capstone Partners, which closed in July 2022. Houlihan Lokey and certain of its affiliates may provide investment banking, financial advisory and/or other financial or consulting services to Greenhill, Mizuho Americas, Mizuho USA, other participants in the Merger or certain of their respective affiliates or security holders in the future, for which Houlihan Lokey and its affiliates may receive compensation. Furthermore, in connection with bankruptcies, restructurings, distressed situations and

similar matters, Houlihan Lokey and certain of its affiliates may have in the past acted, may currently be acting and may in the future act as financial advisor to debtors, creditors, equity holders, trustees, agents and other interested parties (including, without limitation, formal and informal committees or groups of creditors) that may have included or represented and may include or represent, directly or indirectly, or may be or have been adverse to, Greenhill, Mizuho Americas, Mizuho USA, other participants in the Merger or certain of their respective affiliates or security holders, for which advice and services Houlihan Lokey and its affiliates have received and may receive compensation.

Furthermore, as Houlihan Lokey advised the Board of Directors, prior to its engagement by Greenhill, (i) in the ordinary course of business, certain members of the team of Houlihan Lokey professionals advising Greenhill in connection with the Merger (which we refer to as the “Senior Deal Team”) engaged in discussions with Mizuho USA regarding a number of potential acquisition targets and prepared discussion materials in connection therewith, (ii) certain discussion materials provided to Mizuho USA in September 2022 identified Greenhill as a potential acquisition target and included publicly available information regarding Greenhill, and (iii) in April 2023, following Greenhill’s March 2023 request that Houlihan Lokey arrange a meeting between senior management of Mizuho USA and Greenhill regarding a possible transaction, the Senior Deal Team engaged in a discussion with Mizuho USA regarding its possible interest in a transaction with Greenhill and in response to questions from Mizuho USA provided discussion materials to Mizuho USA which included preliminary valuation information for Greenhill based upon publicly available information and certain selected companies and selected transactions.

Greenhill does not, as a matter of course, publicly disclose forecasts or internal projections as to its future performance, revenues, earnings, financial condition or other results given, among other reasons, the inherent uncertainty of the underlying assumptions and estimates, other than, from time to time, estimated ranges of certain financial measures for the current year in its earnings conference calls and investor conference presentations. However, Greenhill is including in this proxy statement certain Management Projections, NOLs and Estimated NOL Tax Savings for Greenhill that was made available to Greenhill’s financial advisor and to Mizuho Americas as part of its due diligence reviews, in each case prior to the execution of the Merger Agreement as described below. We refer to the Management Projections, NOLs and Estimated NOL Tax Savings collectively as the “prospective financial information.” The prospective financial information was prepared by the senior management of Greenhill in connection with the Board of Directors’ evaluation of the Merger and Greenhill’s available strategic alternatives, including its stand-alone plan, each as described in this proxy statement, and was provided to the Board of Directors and Houlihan Lokey, Greenhill’s financial advisor, for its use in the financial analyses performed in connection with Houlihan Lokey’s opinion. A summary of certain significant elements of this information is set forth below and is included in this proxy statement solely for the purpose of providing Greenhill stockholders access to certain nonpublic information made available to Greenhill’s financial advisor.

Greenhill does not endorse the prospective financial information as necessarily predictive of actual future results. Furthermore, although presented with numerical specificity, the prospective financial information reflects numerous estimates and assumptions made by senior management of Greenhill at the time such prospective financial information was prepared or approved for the use of Greenhill’s financial advisor. In addition, because the prospective financial information covers multiple years, such information by its nature becomes subject to greater uncertainty with each successive year. These and the other estimates and assumptions underlying the prospective financial information involve judgments with respect to, among other things, economic, competitive, regulatory and financial market conditions and future business decisions that may not be realized and that are inherently subject to significant business, economic, competitive and regulatory uncertainties and contingencies, including, among other things, the inherent uncertainty of the geopolitical and economic conditions affecting Greenhill’s business and the risks and uncertainties described under the section entitled “Forward-Looking Statements” of this proxy statement and in the reports that Greenhill files with the SEC from time to time, all of which are difficult to predict and many of which are outside the control of Greenhill and will be beyond the control of Mizuho following the completion of the Merger.

There can be no assurance that the underlying assumptions or projected results will be realized, and actual results could differ materially from those reflected in the prospective financial information, whether or not the Merger is completed. Further, these assumptions do not include all potential actions that the senior management

of Greenhill could or might have taken during these time periods. The inclusion in this proxy statement of the prospective financial information below should not be regarded as an indication that Greenhill or the Board of Directors or their advisors considered, or now consider, this prospective financial information to be material information to any Greenhill stockholders, particularly in light of the inherent risks and uncertainties associated with such prospective financial information, or that it should be construed as financial guidance, and it should not be relied on as such. This information was prepared solely for internal use and is subjective in many respects and thus is susceptible to multiple interpretations and periodic revisions based on actual experience and business developments. The prospective financial information is not fact and should not be relied upon as necessarily indicative of actual future results. The prospective financial information also reflects numerous variables, expectations and assumptions available at the time it was prepared as to certain business decisions that are subject to change and does not take into account any circumstances or events occurring after the date it was prepared, including the transactions contemplated by the Merger Agreement or the possible financial and other effects on Greenhill of the Merger, and does not attempt to predict or suggest actual future results of the Surviving Corporation following the completion of the Merger or give effect to the Merger, including the effect of negotiating or executing the Merger Agreement, the costs that may be incurred in connection with consummating the Merger, the potential synergies that may be achieved as a result of the Merger, the effect on Greenhill of any business or strategic decision or action that has been or will be taken as a result of the Merger Agreement having been executed, or the effect of any business or strategic decisions or actions which would likely have been taken if the Merger Agreement had not been executed, but which were instead altered, accelerated, postponed or not taken in anticipation of the Merger. Further, the prospective financial information does not take into account the effect of any possible failure of the Merger to occur. No assurances can be given that if the prospective financial information and the underlying assumptions had been prepared as of the date of this proxy statement, similar assumptions would be used. In addition, the prospective financial information may not reflect the manner in which Mizuho Americas would operate the Surviving Corporation after the Merger.

The accompanying prospective financial information was not prepared for the purpose of, or with a view toward, public disclosure or with a view toward complying with the guidelines established by the American Institute of Certified Public Accountants for preparation and presentation of prospective financial information, published guidelines of the SEC regarding forward-looking statements or generally accepted accounting principles in effect from time to time in the United States of America (which we refer to as “GAAP”).

Subject to the above, the summary of prospective financial information included in this section has been provided by Greenhill’s management as described in this section.

The following table presents Management Projections prepared by Greenhill management for the years ending December 31, 2023 through December 31, 2025 in advance of the execution of the Merger Agreement. The Management Projections, among other estimates, were made available to Mizuho Americas as part of its due diligence reviews and provided by Greenhill management to and used by Houlihan Lokey at the direction of Greenhill management in the financial analyses performed in connection with Houlihan Lokey’s opinion regarding the Merger Consideration under the Merger Agreement:

The following table presents a summary of the NOLs and Estimated NOL Tax Savings, which were calculated from the NOL balances and assumed tax rates provided by Greenhill management to and used by Houlihan Lokey at the direction of Greenhill for purposes of the financial analyses performed in connection with Houlihan Lokey’s opinion regarding the Merger Consideration under the Merger Agreement:

By including in this proxy statement a summary of the prospective financial information, none of Greenhill or any of its advisors or other representatives have made or makes any representation to any person regarding the ultimate performance of Greenhill compared to the information contained in the prospective financial information or that the results reflected in the prospective financial information will be achieved. Greenhill does not undertake any obligation to update or otherwise revise the prospective financial information to reflect circumstances existing since their preparation or to reflect the occurrence of subsequent or unanticipated events, even in the event that any or all of the underlying assumptions are shown to be inappropriate, or to reflect changes in general economic or industry conditions. None of Greenhill or its advisors or other representatives has made, makes or is authorized in the future to make any representation to any stockholder of Greenhill or other person regarding Greenhill’s ultimate performance compared to the information contained in the prospective financial information or that the results reflected in the prospective financial information will be achieved. The prospective financial information included above is provided because it was made available to and considered by the Board of Directors and its financial advisor in connection with the Merger.

In light of the foregoing, and considering that the Special Meeting will be held months after the prospective financial information was prepared, as well as the uncertainties inherent in any forecasted information, Greenhill stockholders are cautioned not to place unwarranted reliance on such information, and are urged to review Greenhill’s most recent SEC filings for a description of its reported financial results. The prospective financial information summarized in this section is not included in this proxy statement in order to induce any holder of Greenhill common stock to vote in favor of the Merger Agreement Proposal or any of the other proposals to be voted on at the Special Meeting.

In considering the recommendation of the Board of Directors with respect to the Merger Proposal and the Compensation Proposal, Greenhill shareholders should be aware that the directors and executive officers of Greenhill have interests in the Merger that may be different from, or in addition to, the interests of Greenhill shareholders generally. The members of the Board of Directors were aware of and considered these interests, among other matters, in evaluating, negotiating and approving the Merger Agreement and in determining to recommend that Greenhill shareholders approve the Merger Agreement Proposal. For more information, see the sections of this proxy statement titled “The Merger—Background of the Merger” and “The Merger—Recommendation of the Board of Directors and Reasons for the Merger.” Such interests are described in more detail below.

Greenhill’s executive officers included in the summary below, all of whom are named executive officers, are:

RSUs. At the Effective Time, each award of RSUs that is outstanding as of immediately prior to the Effective Time will be converted into an unvested Mizuho Cash Award with respect to an amount in cash equal to the product obtained by multiplying (A) the Merger Consideration by (B) the number of shares of Greenhill common stock covered by such award of RSUs immediately prior to the Effective Time, which will otherwise be subject to the same terms and conditions applicable to such award of RSUs (including eligibility to vest in accordance with the vesting schedule set forth in the award agreement evidencing such award of RSUs and any vesting acceleration or treatment upon termination of employment terms set forth in the applicable Greenhill stock plan or such award agreement, to the extent applicable) as of immediately prior to the Effective Time. Any amounts relating to dividend equivalent rights, if any, granted with respect to awards of RSUs that are accrued but unpaid as of the Effective Time will carry over and will be paid if required by and in accordance with the terms and conditions as were applicable to such awards of RSUs immediately prior to the Effective Time.

PSUs. At the Effective Time, each award of PSUs that is outstanding as of immediately prior to the Effective Time will become fully vested with respect to the number of shares of Greenhill common stock covered by such award of PSUs based on the target level of performance and will be converted into the right to receive an amount in cash equal to the product obtained by multiplying (A) the Merger Consideration by (B) the Applicable Number, paid within 10 business days following the Effective Time or such later date as required to avoid the imposition of taxes under Section 409A of the Code. Any amounts relating to dividend equivalent rights, if any, granted with respect to awards of PSUs that are accrued but unpaid as of the Effective Time will be paid within 10 business days following the Effective Time or at such later date required to avoid the imposition of taxes under Section 409A of the Code.

Deferred Cash Awards. At the Effective Time, each Deferred Cash Award that is outstanding as of immediately prior to the Effective Time will be converted into a Mizuho Cash Award with respect to an equivalent amount in cash that has not yet been paid with respect to the Deferred Cash Award as of immediately prior to the Effective Time, which will otherwise be subject to the same terms and conditions applicable to such Deferred Cash Award (including eligibility to vest in accordance with the vesting schedule set forth in the award agreement evidencing such Deferred Cash Award and any vesting acceleration or treatment upon termination of employment terms set forth in the applicable Greenhill stock plan or such award agreement, to the extent applicable) as of immediately prior to the Effective Time.

All such grants of RSUs, PSUs and Deferred Cash Awards were made previously as part of such named executive officers’ annual compensation and unrelated to the Merger. The terms and conditions applicable to the RSUs and Deferred Cash Awards, each of which will be converted into Mizuho Cash Awards, under the applicable Greenhill stock plan and award agreements provide that they will become fully vested and accelerate if the holder’s employment is terminated without “cause” within six months prior (if the committee administering the applicable Greenhill stock plan reasonably determines, in its sole discretion, that such termination was at the behest of an acquiring entity, including Mizuho Americas) or two years following a change in control, including the Merger. The estimated values that would be realized by Greenhill’s named executive officers in respect of their unvested Greenhill awards in connection with the Merger are set forth below in the section of this proxy statement titled “—Quantification of Potential Payments and Benefits to Greenhill’s Named Executive Officers in Connection with the Merger.” None of Greenhill’s non-employee members of the Board of Directors hold any unvested RSUs, PSUs or Deferred Cash Awards for which vesting will be accelerated at the Effective Time.

On May 22, 2023, Mr. Bok entered into an offer letter (which we refer to as the “Bok Offer Letter”) with Mizuho USA, which sets forth the terms of his employment and compensation with Mizuho USA following the Merger. In the event that the Merger Agreement is terminated prior to closing of the Merger, the Bok Offer Letter will be null and void and of no further force or effect. The Bok Offer Letter provides for the following:

The Merger Agreement provides that the Chairman and Chief Executive Officer of Greenhill as of immediately prior to the Effective Time will recommend to Mizuho Americas the annual bonus amount to be paid to each Continuing Employee for the period beginning on January 1, 2023 and ending on March 31, 2024. Mizuho Americas will consider such recommendations from the Chairman and Chief Executive Officer in good faith and will, to the extent not previously paid prior to the Closing or required to be paid on an earlier date in accordance with the applicable Greenhill benefit plan, pay the actual earned amount of such bonus to each Greenhill employee who remains employed in April 2024 in accordance with Mizuho Americas’ standard year-end payment cycle and, to the extent applicable, subject to Mizuho Americas’ applicable deferral schedule (with any deferred amounts to be credited with interest benchmarked to the prevailing consumer price index in accordance with Mizuho Americas’ deferred bonus plan and on a basis no less favorable than as applicable to similarly situated employees of Mizuho Americas or its applicable subsidiaries) and Section 409A of the Code.

Prior to the Closing Date, Greenhill is permitted to enter into a letter agreement with Mr. Rodriguez, who transitioned from his role as Chief Financial Advisor and Chief Operating Officer into that of Senior Advisor on March 1, 2023, to confirm the terms of his employment following the Closing. Any such letter agreement may provide that he will continue to receive his current annual base salary in 2024 and that his employment will terminate no later than the six month anniversary of the Closing Date, which termination will be treated as a termination other than for “cause” for purposes of his then unvested RSUs (and any accrued but unpaid dividend equivalents thereon) and Deferred Cash Awards, which will accelerate and be paid within ten days of such termination, and will entitle him to receive any earned but unpaid annual bonus (including any deferred portion) for the fiscal year ending prior to such termination and a prorated annual bonus (which will not be subject to any deferral requirements) based on levels of performance as determined consistent with the annual bonuses paid to Greenhill employees generally for the fiscal year in which his termination occurs. Such letter agreement will include provisions related to Sections 280G and 4999 of the Code that are substantially similar to those included in the Bok Offer Letter and all payments and benefits to Mr. Rodriguez under the letter agreement in connection with his termination of employment will be subject to Mizuho USA receiving an effective release of claims consistent with the one described in the Bok Offer Letter and Mr. Rodriguez’s compliance with any restrictive covenants applicable to him as of May 22, 2023. However, as of the date of this proxy statement, no such agreement has been discussed or entered into with Mr. Rodriguez.

In addition, any of Greenhill’s executive officers who become officers, directors or employees or who otherwise are retained to provide services to Mizuho Americas, Mizuho USA, the Surviving Corporation or any of their affiliates may enter into new individualized compensation arrangements and may participate in cash or equity incentive or other benefit plans maintained by Mizuho Americas, Mizuho USA, the Surviving Corporation and their affiliates. As of the date of this proxy statement, it has not been determined which, if any, executive officers may continue to provide services to Mizuho Americas, Mizuho USA, the Surviving Corporation or any of their affiliates after the Closing, and other than the Bok Offer Letter and the potential letter agreement with Mr. Rodriguez, no compensation arrangements between such persons have been established or discussed.

The indemnification and exculpation rights, and related rights to advancement of expenses, of any current or former director, officer or employee of Greenhill or its subsidiaries for acts or omissions occurring at or prior to the Effective Time, provided for in their respective organizational documents or other agreement of Greenhill existing as of the date of the Merger Agreement, will be assumed by the Surviving Corporation in the Merger,

and will survive the Merger and will continue in full force and effect in accordance with their terms, and Mizuho Americas will cause the Surviving Corporation to comply with and honor the foregoing obligations. The Merger Agreement requires the Surviving Corporation to indemnify any person who is or was prior to the Effective Time an officer or director of Greenhill or any of its subsidiaries or who was as of the date of the Merger Agreement, or who thereafter commences prior to the Effective Time, serving at the request of Greenhill or any of its subsidiaries as a director or officer of another person (who we refer to as the “Indemnified Parties”) for a period of six years after the Closing against claims, losses, liabilities, damages, judgments, fines, amounts paid in settlement and fees, costs and expenses, including attorneys’ fees and disbursements, incurred in connection with any actual or threatened legal proceeding (including with respect to matters existing or occurring or alleged to occur at or prior to the Effective Time (including the Merger Agreement and the transactions and actions contemplated by the Merger Agreement)) arising from their service as a director or officer of Greenhill or any of its subsidiaries prior to the Effective Time or as a director or officer of another person at the request of Greenhill or any of its subsidiaries as of the date of the Merger Agreement or prior to the Effective Time. In the event of any such legal proceeding, (i) each Indemnified Party will be entitled to advancement of expenses incurred in the defense of any such legal proceeding from the Surviving Corporation within 15 business days of receipt by the Surviving Corporation from the Indemnified Party of a request therefor accompanied by reasonable supporting documentation; provided, that any person to whom expenses are advanced provides an undertaking, if and only to the extent required by the DGCL or the Surviving Corporation’s certificate of incorporation or bylaws, to repay such advances if it is ultimately determined by final adjudication that such person is not entitled to indemnification, and (ii) the Surviving Corporation will cooperate in the defense of any such matter.

In the event that the Surviving Corporation or any of its successors or assigns (i) consolidates with or merges into any other person and is not the continuing or surviving corporation or entity of such consolidation or merger or (ii) transfers or conveys all or substantially all its properties and assets to any person, or if Mizuho Americas dissolves the Surviving Corporation, then, and in each such case, Mizuho Americas will cause proper provision to be made so that the successors and assigns of the Surviving Corporation assume the indemnification obligations set forth in the Merger Agreement.

Mizuho Americas must obtain, or cause to be obtained, at or prior to the Effective Time, a “tail” insurance policy with a claims period of six years from the Effective Time, with respect to directors’ and officers’ liability insurance covering each person currently covered by Greenhill’s directors’ and officers’ liability insurance policy for acts or omissions occurring prior to the Effective Time, on terms that are no less favorable than those of such policy of Greenhill in effect as of the date of the Merger Agreement, which insurance will, prior to the Closing, be in effect and prepaid for such six-year period; provided, that in no event will Mizuho Americas or the Surviving Corporation be required to pay, with respect to the entire six-year period following the Effective Time, premiums for insurance which in the aggregate exceed 300% of the aggregate premiums paid by Greenhill for coverage for the most recent one-year period for which Greenhill obtained such coverage, but in any such case, Mizuho Americas will be obligated to provide such coverage with respect to the entire six-year period following the Effective Time as may be obtained for such 300% amount.

This section sets forth the information required by Item 402(t) of Regulation S-K regarding the compensation for each of Greenhill’s named executive officers that is based on or that otherwise relates to the Merger. The Merger-related compensation payable to these individuals (including their outstanding Greenhill awards) is subject to a non-binding advisory vote of Greenhill’s shareholders, as described above in “—Proposal 2: The Compensation Proposal.” The table below sets forth, for the purposes of this Merger-related compensation disclosure, the amount of payments and benefits that each Greenhill named executive officer would receive, using the following assumptions:

The calculations in the table do not include amounts that Greenhill’s named executive officers were already vested in as of the date of this proxy statement. These amounts also do not reflect compensation actions that may occur after the date of this proxy statement but before the Effective Time, including any additional equity grants, and do not include any compensation that may become payable to Mr. Bok under the Bok Offer Letter described in the section entitled “—Mizuho USA Offer Letter with Scott L. Bok,” which is compensation for, and based on, Mr. Bok’s post-closing employment and service to Mizuho USA and the Surviving Corporation under a bona fide employment agreement.

As a result of the foregoing assumptions, which may or may not actually occur or be accurate on the relevant date, including the assumptions described in the footnotes to the table, the actual amounts, if any, to be received by a named executive officer may materially differ from the amounts set forth below.

For purposes of this disclosure, “single trigger” refers to payments and benefits that arise solely as a result of the completion of the Merger and “double trigger” refers to payments and benefits that require two conditions, which are the completion of the Merger and a qualifying termination of employment.

The consummation of the Merger is not conditioned on Mizuho Americas’ receipt of any financing. Mizuho Americas and Merger Sub have represented in the Merger Agreement that Mizuho Americas and Merger Sub will have available to them at the Effective Time sufficient funds to perform all of their respective obligations under the Merger Agreement to consummate the Merger and the other transactions contemplated by the Merger Agreement, including payment in full of the aggregate Merger Consideration with respect to all shares of Greenhill common stock issued and outstanding immediately prior to the Effective Time (other than (A) Canceled Shares and (B) Dissenting Shares) and the amounts payable to the holders of PSUs, repayment in full of all obligations under the Company Credit Agreement, and payment of all associated fees, costs and expenses. Mizuho Americas and Merger Sub have acknowledged under the Merger Agreement that their obligations under the Merger Agreement are not contingent or conditioned in any manner on obtaining any financing.

The Closing will take place at 9:00 a.m. New York City time on a date that is no later than three business days after the date on which all conditions to the Closing are satisfied or (to the extent permitted by applicable law) waived, which are described below in the section of this proxy statement entitled “The Merger Agreement—Conditions to the Closing of the Merger” (other than the conditions that by their terms are to be satisfied or waived at the Closing, but subject to the satisfaction or (to the extent permitted by applicable law) waiver thereof at or prior to the Closing), or at such other date, time and place as Mizuho Americas and Greenhill may mutually agree in writing. The date on which the Closing takes place is herein referred to as the “Closing Date.”

The Merger will be accounted for using the acquisition method of accounting. Mizuho Americas will be treated as the acquirer for accounting purposes.

Under Delaware law, Greenhill stockholders and beneficial owners are entitled to appraisal rights in connection with the Merger, provided that such holders meet all of the conditions set forth in Section 262 of the DGCL (which we refer to as “Section 262”) and certain conditions described herein are met. Pursuant to Section 262, Greenhill stockholders and beneficial owners who do not vote in favor of the Merger and who comply with the applicable requirements of Section 262 will have the right to seek appraisal of the fair value of such shares as determined by the Delaware Court of Chancery if the Merger is completed. However, immediately before the Merger, Greenhill common stock will be listed on a national exchange. Therefore, pursuant to Section 262(g) of the DGCL, after an appraisal petition has been filed, the Delaware Court of Chancery will dismiss appraisal proceedings as to all Greenhill stockholders and beneficial owners who asserted appraisal rights unless (a) the total number of shares entitled to appraisal exceeds 1% of the issued and outstanding shares of Greenhill common stock as measured in accordance with subsection (g) of Section 262 of the DGCL or (b) the value of the Merger Consideration in respect of such shares exceeds $1 million. Unless the Delaware Court of Chancery, in its discretion, determines otherwise for good cause shown, interest on an appraisal award will accrue and compound quarterly from the Closing Date through the date the judgment is paid at 5% over the Federal Reserve discount rate (including any surcharge) as established from time to time during such period; provided, however, that at any time before the Delaware Court of Chancery enters judgment in the appraisal proceeding, the Surviving Corporation may pay to each stockholder entitled to appraisal an amount in cash, in which case any such interest will accrue after the time of such payment only on the amount that equals the sum of (1) the difference, if any, between the amount so paid and the “fair value” of the shares of Greenhill common stock as determined by the Delaware Court of Chancery and (2) interest theretofore accrued, unless paid at such time. The Surviving Corporation is under no obligation to make such voluntary cash payment before such entry of judgment. In addition, it is possible that the fair value as determined by the Delaware Court of Chancery may be more or less than, or the same as, the Merger Consideration. Stockholders and beneficial owners should note that investment banking opinions as to the fairness from a financial point of view of the consideration payable in a sale transaction, such as the Merger, are not opinions as to, and do not in any manner address, fair value under the DGCL. Greenhill stockholders and beneficial owners electing to exercise appraisal rights must comply with the procedures set forth in Section 262 in order to demand and perfect their rights. Any Greenhill stockholder

or beneficial owner wishing to preserve their rights to appraisal must make a demand for appraisal as described below.

The following is intended as a brief summary of the material provisions of Section 262 required to be followed by Greenhill stockholders or beneficial owners wishing to demand and perfect their appraisal rights. This summary, however, is not a complete statement of all applicable requirements and is subject to and qualified in its entirety by reference to Section 262, the full text of which appears in Annex D to this proxy statement and may be accessed without subscription or cost at the Delaware Code Online (available at https://delcode.delaware.gov/title8/c001/sc09/index.html#262) and is incorporated herein by reference.

Unless otherwise noted herein, all references in this summary to “stockholder” are to the holder of record of shares of Greenhill common stock, and all references to a “beneficial owner” mean any individual, corporation, partnership, unincorporated association or other entity that is the beneficial owner of shares of Greenhill common stock held either in voting trust or by a nominee on behalf of such person.

Under Section 262, where a merger agreement is to be submitted for adoption at a meeting of stockholders, the corporation, not less than 20 days prior to the meeting, must notify each of its stockholders who was such on the record date for notice of such meeting with respect to shares for which appraisal rights are available that appraisal rights are available and include in the notice either a copy of Section 262 or information directing the stockholders to a publicly available electronic resource at which Section 262 may be accessed without subscription or cost.

This proxy statement constitutes Greenhill’s notice to its stockholders and beneficial owners of the availability of appraisal rights in connection with the merger under Section 262 of the General Corporation Law of the State of Delaware, and the full text of Section 262 is set forth in Annex D to this proxy statement and may be accessed without subscription or cost at the Delaware Code Online (available at https://delcode.delaware.gov/title8/c001/sc09/index.html#262).

If you wish to consider exercising your appraisal rights, you should carefully review the text of Section 262 and consult your legal advisor. If you fail to timely and properly comply with the requirements of Section 262, your appraisal rights may be lost. To exercise appraisal rights with respect to your shares of Greenhill common stock, you must:

If you are a stockholder of record and sign and return a proxy card, or submit a proxy through the internet, that does not contain voting instructions, you will effectively waive your appraisal rights because such shares represented by the proxy, unless the proxy is revoked, will be voted for the adoption of the Merger Agreement. Therefore, if you are a stockholder of record and submit a proxy and wish to exercise appraisal rights, you must submit a proxy containing instructions to vote against the adoption of the Merger Agreement or abstain from voting on the adoption of the Merger Agreement. In the case of a beneficial owner, banks, brokers and other nominees that hold shares of Greenhill common stock in “street name” for their customers do not have discretionary authority to vote those shares on the adoption of the Merger Agreement without specific voting instructions from the beneficial owner on such proposal, but such banks, brokers or other nominees will vote such shares as instructed if the beneficial owner provides such instructions. If you are a beneficial owner of shares held in “street name” and instruct your bank, broker or other nominee to vote your shares in favor of the

adoption of the Merger Agreement, and you do not revoke such instruction prior to the vote on the proposal to adopt the Merger Agreement, then such shares will be voted in favor of the adoption of the Merger Agreement, and it will constitute a waiver of your appraisal rights. Therefore, if you are a beneficial owner who wishes to exercise appraisal rights you must either not provide any instructions to your bank, broker or other nominee how to vote on the proposal to adopt the Merger Agreement or instruct your bank, broker or other nominee to vote against the adoption of the Merger Agreement or abstain from voting on such proposal.

A demand for appraisal made by a Greenhill stockholder or beneficial owner must be executed by or on behalf of the holder of record or beneficial owner, as applicable, and must reasonably inform Greenhill of the identity of such stockholder or beneficial owner. In addition, in the case of a demand for appraisal made by a beneficial owner, the demand must also reasonably identify the holder of record of the shares for which the demand is made, be accompanied by documentary evidence of the beneficial owner’s ownership of stock (such as a brokerage or securities account statement containing such information or a letter from the broker or other record holder of such shares confirming such information) and a statement that such documentary evidence is a true and correct copy of what it purports to be, and provide an address at which such beneficial owner consents to receive notices given by the Surviving Corporation under Section 262 and to be set forth on the verified list required by subsection (f) of Section 262 (discussed further below).

Whether made by a Greenhill stockholder or a beneficial owner, a written demand for appraisal must state that the person intends thereby to demand appraisal of the holder’s shares in connection with the Merger.

If the shares of Greenhill common stock are owned of record in a fiduciary capacity, such as by a trustee, guardian or custodian, execution of the demand must be made in that capacity, and if the shares of Greenhill common stock are owned of record by more than one person, as in a joint tenancy and tenancy in common, the demand must be executed by or on behalf of all joint owners. An authorized agent, including an agent for two or more joint owners, may execute a demand for appraisal on behalf of a holder of record or beneficial owner; however, the agent must identify the record owner or owners (and, if any by an authorized agent of any beneficial owner or owners, must identify the beneficial owner or owners) and expressly disclose the fact that, in executing the demand, the agent is acting as agent for such owner or owners. A record holder who holds shares of Greenhill common stock as a nominee for others may exercise his, her or its right of appraisal with respect to the shares of Greenhill common stock held for one or more beneficial owners, while not exercising this right for other beneficial owners. In that case, the written demand should state the number of shares of Greenhill common stock as to which appraisal is sought. Where no number of shares of Greenhill common stock is expressly mentioned, the demand for appraisal will be presumed to cover all shares of Greenhill common stock held in the name of the record holder.

Failure to follow the procedures set forth in Section 262 may result in the loss, termination or waiver of appraisal rights. Stockholders or beneficial owners who vote in favor of the adoption and approval of the Merger Agreement will not have a right to have the fair value of their shares of Greenhill common stock determined. However, failure to vote in favor of the Merger Agreement is not sufficient to perfect appraisal rights. If you desire to exercise your appraisal rights, you must also submit to Greenhill a written demand for payment of the fair value of your Greenhill common stock. A Greenhill stockholder’s or beneficial owner’s failure to make such a written demand prior to the taking of the vote on the proposal to adopt the Merger Agreement will constitute a waiver of appraisal rights.

All demands for appraisal should be delivered to: Greenhill, Attention: Corporate Secretary, 1271 Avenue of the Americas New York, NY 10020.

If the Merger is completed, the Surviving Corporation, within 10 days after the Closing Date, will notify each Greenhill stockholder who has properly made a written demand for appraisal pursuant to Section 262 and has not voted in favor of the Merger, and any beneficial owner who has demanded appraisal in such person’s name pursuant to Section 262, that the Merger has become effective and the effective date thereof.

Within 120 days after the Closing Date, the Surviving Corporation or any record holder or beneficial owner of shares of Greenhill common stock who has demanded appraisal of such person’s shares and is entitled to appraisal rights may file a petition with the Delaware Court of Chancery, with a copy served on the Surviving Corporation in the case of a petition filed by a stockholder or beneficial owner, demanding a determination of the value of the Greenhill common stock held by all such persons entitled to appraisal. The Surviving Corporation is under no obligation to and has no present intention to file a petition and stockholders and beneficial owners should not assume that the Surviving Corporation will file a petition or initiate any negotiations with respect to the fair value of Greenhill common stock. Accordingly, it is the obligation of the stockholders and beneficial owners of shares of Greenhill common stock to initiate all necessary action to perfect their appraisal rights within the time prescribed in Section 262. If no such petition is filed by a record holder or beneficial owner of shares of Greenhill common stock, or by the Surviving Corporation, within the 120-day period specified in Section 262, Greenhill stockholders’ and beneficial owners’ rights to an appraisal will cease. If a petition for appraisal is duly filed by a Greenhill stockholder or beneficial owner and a copy of the petition is served on the Surviving Corporation, the Surviving Corporation will then be obligated, within 20 days after such service, to file in the office of the Register in Chancery in which the petition was filed a duly verified list (which we refer to as the “verified list”) containing the names and addresses of all Greenhill stockholders and beneficial owners who have demanded payment for their shares of Greenhill common stock and with whom agreements as to the value of their shares of Greenhill common stock have not been reached by the Surviving Corporation. Upon the filing of any such petition, the Delaware Court of Chancery may order that notice of the time and place fixed for the hearing on the petition be mailed to the Surviving Corporation and all persons shown on the verified list at the addresses stated therein. The costs of these notices are borne by the Surviving Corporation. After notice to the Surviving Corporation and Greenhill stockholders and beneficial owners as required by the court of Greenhill common stock, the Delaware Court of Chancery is empowered to conduct a hearing upon the petition, and to determine those Greenhill stockholders and beneficial owners who have complied with Section 262 of the DGCL and who have become entitled to the appraisal rights provided thereby.

The Delaware Court of Chancery may require the Greenhill stockholders and beneficial owners who have demanded appraisal for their shares of Greenhill common stock to submit their stock certificates (if any) to the Register in Chancery for notation thereon of the pendency of the appraisal proceedings, and if any Greenhill stockholder or beneficial owner fails to comply with that direction, the Delaware Court of Chancery may dismiss the proceedings as to that stockholder or beneficial owner.

After the Delaware Court of Chancery determines the Greenhill stockholders and beneficial owners entitled to appraisal, the appraisal proceeding will be conducted in accordance with the rules of the Delaware Court of Chancery, including any rules specifically governing appraisal proceedings. Through this proceeding, the Delaware Court of Chancery will determine the “fair value” of the shares, exclusive of any element of value arising from the accomplishment or expectation of the Merger, together with interest, to be paid, if any, upon the amount determined to be “fair value” in an appraisal proceeding. Unless the Delaware Court of Chancery in its discretion determines otherwise for good cause shown, interest from the Closing Date through the date of payment of the judgment will be compounded quarterly and will accrue at 5% over the Federal Reserve discount rate (including any surcharge) as established from time to time during the period between the Closing Date and the date of payment of the judgment. However, at any time before the Delaware Court of Chancery’s entry of judgment in the proceedings, the Surviving Corporation may pay to each Greenhill stockholder and beneficial owner entitled to appraisal an amount in cash, which is referred to as a voluntary cash payment, in which case interest will accrue thereafter only upon the sum of (i) the difference, if any, between the amount so paid by the Surviving Corporation and the fair value of the shares as determined by the Delaware Court of Chancery and (ii) interest theretofore accrued, unless paid at that time.

In determining the fair value of the shares, the Delaware Court of Chancery will take into account all relevant factors. In Weinberger v. UOP, Inc., the Delaware Supreme Court discussed the factors that could be considered in determining fair value in an appraisal proceeding, stating that “proof of value by any techniques or methods that are generally considered acceptable in the financial community and otherwise admissible in court” should be considered, and that “fair price obviously requires consideration of all relevant factors involving the value of a company.” The Delaware Supreme Court stated that, in making this determination of fair value, the

court must consider market value, asset value, dividends, earnings prospects, the nature of the enterprise and any other facts that could be ascertained as of the date of the merger that throw any light on future prospects of the corporation. Section 262 provides that fair value is to be “exclusive of any element of value arising from the accomplishment or expectation of the merger.” In Cede & Co. v. Technicolor, Inc., the Delaware Supreme Court stated that such exclusion is a “narrow exclusion [that] does not encompass known elements of value,” but which rather applies only to the speculative elements of value arising from such accomplishment or expectation. In Weinberger, the Delaware Supreme Court also stated that “elements of future value, including the nature of the enterprise, which are known or susceptible of proof as of the date of the merger and not the product of speculation, may be considered.”

Greenhill stockholders and beneficial owners who consider seeking appraisal should be aware that the fair value of their shares under Section 262 could be more than, the same as, or less than the value of the Merger Consideration provided for in the Merger Agreement without the exercise of appraisal rights. No representation is made as to the outcome of the appraisal of fair value as determined by the Delaware Court of Chancery.

Upon application by the Surviving Corporation or by any person entitled to participate in the appraisal proceeding, the Delaware Court of Chancery may, in its discretion, proceed to trial upon the appraisal prior to the final determination of the persons entitled to an appraisal. Any person whose name appears on the verified list may participate fully in all proceedings until it is finally determined that such person is not entitled to appraisal rights. When the fair value of the shares is determined, the Delaware Court of Chancery will direct the payment of such value, with interest thereon, if any, to the persons entitled thereto and upon such terms and conditions as the Delaware Court of Chancery may order. The Delaware Court of Chancery’s decree may be enforced as other decrees in the Delaware Court of Chancery may be enforced. The Delaware Court of Chancery may determine the cost of the appraisal proceeding (which do not include attorneys’ fees or the fees and expenses of experts) and assess it against the parties as the Delaware Court of Chancery deems equitable. Upon application of a person whose name appears on a verified list and who participated in the proceeding and incurred expenses in connection therewith, the Delaware Court of Chancery may order that all or a portion of such expenses, including, without limitation, reasonable attorneys’ fees and the fees and expenses of experts, be charged pro rata against the value of all shares of Greenhill common stock entitled to appraisal. In the absence of a court determination or assessment, each party will bear its own expenses.

Any Greenhill stockholder or beneficial owner who has demanded appraisal in compliance with Section 262 will not, after the Effective Time, be entitled to vote such stock for any purpose or receive payment of dividends or other distributions, if any, on the Greenhill common stock, except for dividends or distributions, if any, payable to person at a date before the Closing.

If you submit a written demand for appraisal of your shares of Greenhill common stock and otherwise properly perfect your appraisal rights, you may, upon written request mailed to the Surviving Corporation within 120 days after the Closing Date, receive a statement identifying (1) the aggregate number of shares of Greenhill common stock which were not voted in favor of the adoption and approval of the Merger Agreement and with respect to which Greenhill has received written demands for appraisal; and (2) the aggregate number of Greenhill stockholders or beneficial owners holding or owning such shares (provided that, in the case of a demand made by a beneficial owner in such person’s name, the record holder of such shares will not be considered a separate stockholder holding such shares for purposes of such aggregate number). This statement will be given to you within 10 days after receiving your written request, or within 10 days after the expiration of the period for delivery of demands for appraisal, whichever is later.

At any time within 60 days after the Closing Date, any person entitled to appraisal rights who has not commenced an appraisal proceeding or joined that proceeding as a named party may withdraw such person’s demand for appraisal in respect of some or all of such person’s shares and accept the Merger Consideration offered pursuant to the Merger Agreement with respect to the shares subject to the withdrawal by delivering to the Surviving Corporation a written withdrawal of the demand for appraisal. Once a petition for appraisal is filed with the Delaware Court of Chancery, however, no appraisal proceeding may be dismissed as to any person without the approval of the Delaware Court of Chancery and such approval may be conditioned upon such terms

as the Delaware Court of Chancery deems just; provided that this sentence does not affect the right of any person who has not commenced an appraisal proceeding or joined that proceeding as a named party to withdraw such person’s demand in respect of some or all of such person’s shares and to accept the terms offered under the Merger Agreement with respect to the shares subject to the withdrawal within 60 days after the Closing Date. If you withdraw your demand or otherwise lose your appraisal rights for any reason, you will be deemed to have accepted the terms of the Merger Agreement, which are summarized in this document. The Merger Agreement is attached in its entirety as Annex A.

The foregoing summary is not intended to be a complete statement of the procedures for exercising appraisal rights under Section 262 and is qualified in its entirety by reference to the full text of Section 262, a copy of which is attached as Annex D to this proxy statement and the full text of which may be accessed without subscription or cost at the Delaware Code Online (available at https://delcode.delaware.gov/title8/c001/sc09/index.html#262). Greenhill urges any stockholder or beneficial owner wishing to exercise appraisal rights, if any, to read this summary and Section 262 carefully, and to consult legal counsel before attempting to exercise appraisal rights. Failure to comply with all of the procedures set forth in Section 262 may result in the loss of your statutory appraisal rights.

The following is a general discussion of certain U.S. federal income tax consequences of the Merger that may be relevant to U.S. Holders (as defined below) of shares of Greenhill common stock whose shares of Greenhill common stock are converted into the right to receive cash pursuant to the Merger. This discussion is limited to U.S. Holders who hold their shares of Greenhill common stock as “capital assets” within the meaning of Section 1221 of the Code (generally, property held for investment). This discussion does not address U.S. federal income tax consequences with respect to holders other than U.S. Holders. This discussion is based upon the Code, Treasury Regulations promulgated under the Code, rulings and other published positions of the Internal Revenue Service (which we refer to as the “IRS”) and judicial decisions, all as in effect on the date of this proxy statement and all of which are subject to change or differing interpretations at any time, possibly with retroactive effect. Any such change or differing interpretation could affect the accuracy of the statements and conclusions set forth in this discussion. No assurance can be given that the IRS would not assert, or that a court would not sustain, a position contrary to any of the tax considerations described in this discussion. No advance ruling has been or will be sought from the IRS, and no opinion of counsel has been or will be rendered, regarding any matter discussed below.

For purposes of this discussion, a “U.S. Holder” means a beneficial owner of shares of Greenhill common stock that is for U.S. federal income tax purposes:

This discussion is for general information purposes only and does not purport to be a complete analysis of all of the U.S. federal income tax considerations that may be relevant to particular holders in light of their particular facts and circumstances, or to Greenhill stockholders subject to special rules under the U.S. federal income tax laws, including, for example:

This discussion does not address any U.S. federal tax considerations other than those pertaining to the income tax (such as estate, gift or other non-income tax consequences) or any state, local or foreign income or non-income tax considerations. In addition, this discussion does not address any considerations arising under the unearned income Medicare contribution tax pursuant to the Health Care and Education Reconciliation Act of 2010 or any considerations in respect of the Foreign Account Tax Compliance Act of 2010 (including the Treasury Regulations and administrative guidance promulgated thereunder and intergovernmental agreements entered into pursuant thereto or in connection therewith and any laws, regulations or practices adopted in connection with any such agreement).

If any entity or arrangement treated as a partnership for U.S. federal income tax purposes is a beneficial owner of shares of Greenhill common stock, the U.S. federal income tax treatment of a partner in such partnership generally will depend upon the status of the partner, the activities of the partner and the partnership and certain determinations made at the partner level. Accordingly, entities or arrangements treated as partnerships holding shares of Greenhill common stock, and any partners therein, should consult their tax advisors as to the particular tax consequences to them of the Merger.

THE U.S. FEDERAL INCOME TAX TREATMENT OF THE TRANSACTIONS DISCUSSED HEREIN TO ANY PARTICULAR GREENHILL STOCKHOLDER WILL DEPEND ON THE GREENHILL STOCKHOLDER’S PARTICULAR TAX CIRCUMSTANCES. YOU SHOULD CONSULT YOUR TAX ADVISOR WITH RESPECT TO THE SPECIFIC TAX CONSEQUENCES TO YOU OF THE MERGER IN LIGHT OF YOUR OWN PARTICULAR CIRCUMSTANCES, INCLUDING U.S. FEDERAL, STATE, LOCAL AND NON-U.S. INCOME AND OTHER TAX CONSEQUENCES.

The receipt of cash by a U.S. Holder in exchange for shares of Greenhill common stock pursuant to the Merger will be a taxable transaction for U.S. federal income tax purposes. In general, for U.S. federal income tax purposes, a U.S. Holder who receives cash in exchange for Greenhill common stock pursuant to the Merger will recognize gain or loss in an amount equal to the difference, if any, between the amount of cash received in the Merger and the U.S. Holder’s adjusted tax basis in the shares of Greenhill common stock surrendered pursuant to

the Merger. A U.S. Holder’s adjusted tax basis generally will equal the amount that such U.S. Holder paid for the shares of Greenhill common stock. Any gain or loss will generally be long-term capital gain or loss if such U.S. Holder’s holding period in such shares is more than one year at the time of the completion of the Merger. Long-term capital gains of certain non-corporate holders, including individuals, currently are subject to U.S. federal income tax at preferential rates. The deductibility of capital losses is subject to limitations. If a U.S. Holder acquired different blocks of Greenhill common stock at different times or different prices, such U.S. Holder must determine its adjusted tax basis and holding period separately with respect to each block of Greenhill common stock.

Generally, information reporting requirements may apply in connection with payments made to U.S. Holders in connection with the Merger.

Backup withholding of tax (currently, at a rate of 24%) generally will apply to the proceeds received by a U.S. Holder pursuant to the Merger, unless the U.S. Holder provides the applicable withholding agent with a properly completed and executed IRS Form W-9 providing such U.S. Holder’s correct taxpayer identification number and certifying that such U.S. Holder is a “United States person” (within the meaning of the Code) and that such U.S. Holder is not subject to backup withholding, or otherwise establishes an exemption, and otherwise complies with the backup withholding rules.

Backup withholding is not an additional tax. The amount of any backup withholding from a payment to a U.S. Holder may be refunded by the IRS or credited against such U.S. Holder’s U.S. federal income tax liability, if any, provided that the required information is timely furnished to the IRS.

THIS DISCUSSION IS FOR GENERAL INFORMATION PURPOSES ONLY. IT DOES NOT ADDRESS TAX CONSIDERATIONS THAT MAY VARY WITH, OR ARE CONTINGENT ON, YOUR INDIVIDUAL CIRCUMSTANCES OR THE APPLICATION OF ANY U.S. NON-INCOME TAX LAWS OR THE LAWS OF ANY STATE, LOCAL OR NON-U.S. JURISDICTION, AND HOLDERS SHOULD CONSULT THEIR TAX ADVISORS REGARDING SUCH MATTERS AND THE TAX CONSEQUENCES OF THE MERGER TO THEM IN LIGHT OF THEIR PARTICULAR CIRCUMSTANCES.

Under the Merger Agreement, each of Greenhill and Mizuho Americas has agreed to use its respective reasonable best efforts to obtain the Requisite Regulatory Approvals as soon as practicable and in any event no later than the Termination Date, including an obligation to defend against any litigation challenging the Merger. However, Mizuho Americas is not obligated to agree to any structural or behavioral remedy required by any governmental authority.

The Merger is subject to the HSR Act. A transaction notifiable under the HSR Act may not be completed until the expiration or termination of a 30-day waiting period following the parties’ filings of their HSR Act notification and report forms. If the Federal Trade Commission (which we refer to as the “FTC”) or the Antitrust Division of the Department of Justice (which we refer to as the “DOJ”) issues a request for additional information and documentary materials (which we refer to as a “Second Request”) prior to the expiration of the initial waiting period, the parties must observe a second 30-day waiting period, which would begin to run only after the parties have substantially complied with the Second Request, unless the waiting period is terminated earlier or the parties otherwise agree to extend the waiting period. Greenhill and Mizuho Americas made the filings required under the HSR Act on June 6, 2023, and the initial 30-day waiting period is scheduled to expire at 11:59 p.m., Eastern Time, on July 6, 2023, unless otherwise extended.

At any time before or after consummation of the Merger, notwithstanding the termination or expiration of the waiting period under the HSR Act, the FTC or the DOJ could take such action under the antitrust laws as it deems necessary or desirable in the public interest, including seeking to enjoin the completion of the Merger, seeking divestiture of substantial assets of the parties, or requiring the parties to license or hold separate assets or terminate existing relationships and contractual rights. At any time before or after the completion of the Merger,

any state could take such action under the antitrust laws as it deems necessary or desirable in the public interest. Such action could include seeking to enjoin the completion of the Merger or seeking divestiture of substantial assets of the parties. Private parties may also seek to take legal action under the antitrust laws under certain circumstances. We cannot be certain that a challenge to the Merger will not be made or that, if a challenge is made, we will prevail.

Completion of the transactions contemplated by the Merger Agreement is subject to approval in:

In each case, the Merger cannot be completed until the parties obtain clearance or approval to consummate the Merger or the applicable waiting periods have expired or been terminated. The relevant regulatory authorities could take such actions under the applicable regulatory laws as they deem necessary or desirable, including seeking divestiture of substantial assets of the parties or requiring the parties to license, or hold separate, assets or terminate existing relationships and contractual rights.

The following summarizes the provisions of the Merger Agreement. The descriptions of the Merger Agreement in this summary and elsewhere in this proxy statement are not complete and are qualified in their entirety by reference to the Merger Agreement, a copy of which is attached to this proxy statement as Annex A and incorporated into this proxy statement by reference. You should carefully read and consider the entire Merger Agreement, which is the legal document that governs the Merger, because this summary may not contain all of the information about the Merger Agreement that is important to you. The rights and obligations of the parties are governed by the express terms of the Merger Agreement and not by this summary or any other information contained in this proxy statement.

The representations, warranties, covenants and agreements described below and included in the Merger Agreement (a) were made only for purposes of the Merger Agreement and as of specific dates; (b) were made solely for the benefit of the parties to the Merger Agreement; and (c) may be subject to important qualifications, limitations and supplemental information agreed to by Greenhill, Mizuho Americas and Merger Sub in connection with negotiating the terms of the Merger Agreement. In addition, the representations and warranties have been included in the Merger Agreement for the purpose of allocating contractual risk between Greenhill, Mizuho Americas and Merger Sub rather than to establish matters as facts, and may be subject to standards of materiality applicable to such parties that differ from those applicable to investors. Except for (i) the right of the Greenhill stockholders to receive the Merger Consideration following the Effective Time in accordance with the terms of the Merger Agreement and (ii) the right of the holders of RSUs, PSUs or Deferred Cash Awards to receive the consideration set forth in the Merger Agreement, Greenhill stockholders are not third-party beneficiaries under the Merger Agreement and should not rely on the representations, warranties, covenants and agreements or any descriptions thereof as characterizations of the actual state of facts or condition of Greenhill, Mizuho Americas or Merger Sub or any of their respective affiliates or businesses. Moreover, information concerning the subject matter of the representations and warranties may change after the date of the Merger Agreement. In addition, you should not rely on the covenants in the Merger Agreement as actual limitations on the respective businesses of Greenhill, Mizuho Americas and Merger Sub, because the parties may take certain actions that are either expressly permitted in the confidential disclosure schedules to the Merger Agreement or as otherwise consented to by the appropriate party, which consent may be given without prior notice to the public. The Merger Agreement is described below, and included as Annex A, only to provide you with information regarding its terms and conditions, and not to provide any other factual information regarding Greenhill, Mizuho Americas, Merger Sub, or their respective businesses. Accordingly, the representations, warranties, covenants and other agreements in the Merger Agreement should not be read alone, and you should read the information provided elsewhere in this document and in our filings with the SEC regarding Greenhill and our business.

The Merger Agreement provides that, in accordance with the DGCL and upon the terms and subject to the conditions of the Merger Agreement, at the Effective Time, Merger Sub will merge with and into Greenhill, the separate existence of Merger Sub will cease and Greenhill will be the Surviving Corporation. From and after the Effective Time, subject to the terms and conditions of the Merger Agreement and the DGCL, all the property, rights, powers, privileges, and franchises of Greenhill and Merger Sub will be vested in the Surviving Corporation, and all of the debts, liabilities and duties of Greenhill and Merger Sub will become the debts, liabilities and duties of the Surviving Corporation.

The Merger Agreement also provides that the parties will take all necessary action such that, from and after the Effective Time, the directors of Merger Sub immediately prior to the Effective Time will be the directors of the Surviving Corporation until the earlier of their death, resignation or removal or until their respective successors are duly elected and qualified, as the case may be, in each case in accordance with the certificate of incorporation and bylaws of the Surviving Corporation. In addition, unless otherwise determined by Mizuho Americas prior to the Effective Time, the parties will take all necessary action such that, from and after the

Effective Time, the officers of Merger Sub immediately prior to the Effective Time will be the officers of the Surviving Corporation until the earlier of their death, resignation or removal or until their respective successors are duly elected and qualified, as the case may be, in each case in accordance with the certificate of incorporation and bylaws of the Surviving Corporation.

As of the Effective Time, the certificate of incorporation of Greenhill will be amended and restated in its entirety to read as set forth in Exhibit A to the Merger Agreement and such amended and restated certificate of incorporation will become the certificate of incorporation of the Surviving Corporation, and the parties will take all necessary action such that the bylaws of Greenhill will be amended and restated as of the Effective Time in their entirety to read as set forth in Exhibit B to the Merger Agreement and such amended and restated bylaws will become the bylaws of the Surviving Corporation, in each case, until thereafter amended in accordance with the applicable provisions of the DGCL, the Merger Agreement, and such certificate of incorporation and such bylaws.

The Closing will take place at 9:00 a.m. New York City time on the date that is no more than three business days after the date on which all conditions to Closing are satisfied or (to the extent permitted by applicable law) waived, which are described below in the section of this proxy statement entitled “—Conditions to the Closing of the Merger,” (other than the conditions which by their nature are to be satisfied at the Closing, but subject to the satisfaction or (to the extent permitted by applicable law) waiver thereof at or prior to the Closing), or such other date, time and place as Mizuho Americas and Greenhill may mutually agree in writing.

On the Closing Date, the parties will file a certificate of merger with respect to the Merger with the Secretary of State for the State of Delaware as provided under the DGCL. The Merger will become effective at such date and time as the certificate of merger is duly filed with the Secretary of State for the State of Delaware or, to the extent permitted by applicable law, at such subsequent date and time as Mizuho Americas and Greenhill may mutually agree and specify in the certificate of merger.

At the Effective Time, by virtue of the Merger and without any action on the part of the holders of any shares of Greenhill common stock, each share of Greenhill common stock (other than any Canceled Shares and Dissenting Shares) issued and outstanding immediately prior to the Effective Time will be converted automatically into the right to receive the Merger Consideration of $15.00 in cash, without interest, subject to any required tax withholding.

At the Effective Time, each award of RSUs that is outstanding as of immediately prior to the Effective Time will be converted into an unvested Mizuho Cash Award with respect to an amount in cash equal to the product obtained by multiplying (A) the Merger Consideration by (B) the number of shares of Greenhill common stock covered by such award of RSUs immediately prior to the Effective Time, which Mizuho Cash Award will otherwise be subject to the same terms and conditions applicable to such award of RSUs (including eligibility to vest in accordance with the vesting schedule set forth in the award agreement evidencing such award of RSUs and any vesting acceleration or treatment upon termination of employment terms set forth in the applicable Greenhill stock plan or award agreement, to the extent applicable) as of immediately prior to the Effective Time. Any amounts relating to dividend equivalent rights, if any, granted with respect to such RSUs that are accrued but unpaid as of the Effective Time will carry over and will be paid if required by and in accordance with the terms and conditions as were applicable to such awards of RSUs immediately prior to the Effective Time.

At the Effective Time, each award of PSUs that is outstanding immediately prior to the Effective Time will become fully vested with respect to the number of shares of Greenhill common stock covered by such award of PSUs based on the target level of performance and will be converted into the right to receive an amount in cash equal to the product obtained by multiplying (A) the Merger Consideration by (B) the Applicable Number, paid within 10 business days following the Effective Time or such later date as required to avoid the imposition of taxes under Section 409A of the Code. Any amounts relating to dividend equivalent rights, if any, granted with respect to awards of PSUs that are accrued but unpaid as of the Effective Time will be paid within 10 business days following the Effective Time or at such later date required to avoid the imposition of taxes under Section 409A of the Code.

At the Effective Time, each Deferred Cash Award that is outstanding immediately prior to the Effective Time will be converted into a Mizuho Cash Award with respect to an equivalent amount in cash that has not yet been paid with respect to the Deferred Cash Award as of immediately prior to the Effective Time, which will otherwise be subject to the same terms and conditions applicable to such Deferred Cash Award (including eligibility to vest in accordance with the vesting schedule set forth in the award agreement evidencing such Deferred Cash Award and any vesting acceleration or treatment upon termination of employment terms set forth in the applicable Greenhill stock plan or award agreement, to the extent applicable) as of immediately prior to the Effective Time.

Prior to the Effective Time, Mizuho Americas will appoint a paying agent reasonably acceptable to Greenhill to act as agent (which we refer to as the “Paying Agent”) for the holders of shares of Greenhill common stock to receive the aggregate Merger Consideration to which the holders of such shares of Greenhill common stock become entitled pursuant to the Merger Agreement. No later than substantially concurrently with the Effective Time, Mizuho Americas will deposit (or cause to be deposited) with the Paying Agent cash sufficient to pay the aggregate Merger Consideration with respect to all of the shares of Greenhill common stock issued and outstanding immediately prior to the Effective Time (other than the Canceled Shares and Dissenting Shares) (which we refer to as the “Payment Fund”). To the extent the Payment Fund diminishes for any reason below the level required to make prompt payment of any outstanding Merger Consideration to be paid in exchange for shares of Greenhill common stock entitled to receive the Merger Consideration pursuant to the Merger Agreement, Mizuho Americas and the Surviving Corporation will promptly replace or restore the lost portion of such Payment Fund so as to ensure that it is, at all times, maintained at a level sufficient to make such payment. The Payment Fund will not be used for any purpose other than to pay the Merger Consideration in the Merger. The Payment Fund will be invested by the Paying Agent as directed by the Surviving Corporation. If any portion of the cash made available to the Paying Agent is in respect of any Dissenting Shares, such cash will be returned to Mizuho Americas upon demand.

As soon as reasonably practicable after the Effective Time and in any event within five business days following the Closing Date, Mizuho Americas will mail or will cause the Paying Agent to mail to each holder of record of shares of Greenhill common stock as of immediately prior to the Effective Time, in each case whose shares of Greenhill common stock were converted into the right to receive the Merger Consideration pursuant to the Merger Agreement, (i) a form of letter of transmittal (which will (A) include an accompanying IRS Form W-9 or the applicable IRS Form W-8, (B) specify that delivery will be effected and risk of loss and title to the certificates or evidence of shares in book-entry form that immediately prior to the Effective Time represented any such shares (which we refer to as “Certificates”) held by such person will pass only upon proper delivery of the Certificates to the Paying Agent, and (C) be in a form and have such other provisions (including customary provisions regarding delivery of an “agent’s message” with respect to shares held in book-entry form) as Mizuho Americas may reasonably specify) and (ii) instructions for use in effecting the surrender of the Certificates in exchange for the Merger Consideration. Upon surrender of a Certificate for cancelation to the Paying Agent or to such other agent or agents as may be appointed by Mizuho Americas, together with such letter of transmittal, duly completed and validly executed, and such other documents as may reasonably be required by the Paying Agent, the holder of such Certificate will be entitled to receive in exchange therefor the

Merger Consideration with respect to each share of Greenhill common stock represented by such Certificate, and the Certificate so surrendered will be cancelled.

In the event of a transfer of ownership of Greenhill common stock that is not registered in the stock transfer books of Greenhill, payment of the Merger Consideration in exchange therefor may be made to a person other than the person in whose name the Certificate so surrendered is registered, if such Certificate is properly endorsed or otherwise in proper form for transfer, and the person requesting such payment pays any stamp, transfer or other similar taxes required by reason of the payment to a person other than the registered holder of such Certificate or otherwise establishes to the satisfaction of the Surviving Corporation that such tax has been paid or is not applicable. No interest will be paid or will accrue on the cash payable upon surrender of any Certificate.

If any Certificate has been lost, stolen, defaced or destroyed, upon the making of an affidavit of that fact by the person claiming such Certificate to be lost, stolen, defaced or destroyed and, if required by the Surviving Corporation, the posting by such person of a bond in such amount as the Surviving Corporation may direct as indemnity against any claim that may be made against it with respect to such Certificate, the Paying Agent or the Surviving Corporation, as the case may be, will pay the Merger Consideration in respect of such lost, stolen, defaced or destroyed Certificate. Until surrendered as contemplated by the Merger Agreement, each Certificate will be deemed at any time after the Effective Time to represent only the right to receive the Merger Consideration in accordance with the terms of the Merger Agreement.

At any time following the 12-month anniversary of the Closing Date, the Surviving Corporation will be entitled to require the Paying Agent to deliver to it any portion of the Payment Fund (including any interest or other amounts received with respect thereto) that has not been disbursed to holders of Certificates, and, thereafter, subject to certain time limitations, such holders will be entitled to look only to Mizuho Americas and the Surviving Corporation (subject to abandoned property, escheat or other similar laws) as general creditors thereof with respect to the payment of any Merger Consideration that may be payable upon surrender of any Certificates held by such holders, as determined pursuant to the Merger Agreement, without any interest thereon.

Each of the Paying Agent, Mizuho Americas, Greenhill and the Surviving Corporation will be entitled to deduct and withhold from the Merger Consideration and any other amounts payable pursuant to the Merger Agreement (including amounts payable to any holder of PSUs) such amounts as are required to be deducted and withheld with respect to the making of such payment under the Code, or any applicable provision of state, local or foreign tax law. To the extent that amounts are so deducted and withheld and paid over to the appropriate taxing authority, such amounts will be treated for all purposes of the Merger Agreement as having been paid to the person in respect of which such deduction and withholding was made.

The Merger Agreement contains representations and warranties of Greenhill, Mizuho Americas and Merger Sub.

In the Merger Agreement, Greenhill has made representations and warranties to Mizuho Americas and Merger Sub that are subject, in some cases, to specified exceptions and qualifications contained in the Merger Agreement. These representations and warranties relate to, among other things:

Some of the representations and warranties in the Merger Agreement made by Greenhill are qualified as to materiality or “Material Adverse Effect” (that is, they will not be deemed to be untrue or incorrect unless their failure to be true or correct is material or would result in a Material Adverse Effect). In addition, certain of the representations and warranties of Greenhill in the Merger Agreement are subject to knowledge qualifications, which means that those representations and warranties would not be deemed untrue, inaccurate or incorrect as a result of matters of which certain officers of Greenhill did not have actual knowledge.

For purposes of the Merger Agreement, “Material Adverse Effect” means any state of facts, change, development, event, effect, condition, or occurrence (each of which we refer to as an “Effect”) that, individually or in the aggregate, has had, or would reasonably be excepted to have, a material adverse effect on the business, financial condition or results of operations of Greenhill and its subsidiaries, taken as a whole; provided, that in no event will any of the following Effects, alone or in combination, be deemed to constitute, or be taken into account, in determining whether there has been, or would be, a Material Adverse Effect:

except that, any of the matters in the second or third bullets above will be taken into account in determining whether a Material Adverse Effect has occurred if any only to the extent they materially disproportionately adversely affect Greenhill and its subsidiaries, taken as a whole, as compared with other companies operating in the industries in which Greenhill and its subsidiaries operate.

In the Merger Agreement, Mizuho Americas and Merger Sub have made representations and warranties to Greenhill. Some of the representations and warranties in the Merger Agreement made by Mizuho Americas and Merger Sub are qualified as to materiality or “Parent Material Adverse Effect” (that is, they will not be deemed to be untrue or incorrect unless their failure to be true or correct is material or would result in a Parent Material Adverse Effect). A “Parent Material Adverse Effect” means any Effect that, individually or in the aggregate with one or more other Effects, would or would reasonably be expected to prevent, materially impede or materially delay the Closing or the ability of Merger Sub or Mizuho Americas to perform their respective obligations under the Merger Agreement or consummate the Merger or the other transactions contemplated by the Merger Agreement on a timely basis and in any event on or before the Termination Date. The representations and warranties of Mizuho Americas and Merger Sub relate to, among other things:

The representations and warranties contained in the Merger Agreement will not survive the consummation of the Merger.

Prior to the Closing, subject to certain agreed exceptions or except as consented to in writing by Mizuho Americas (which consent may not be unreasonably withheld, conditioned or delayed), Greenhill has agreed to, and has agreed to cause each of its subsidiaries to, use commercially reasonable efforts to (i) carry on its and their businesses in all material respects in the ordinary course consistent with past practice and (ii) to the extent consistent therewith, keep available the services of their present officers and other employees, and preserve substantially intact their relationships with their business partners and others having material business dealings with them.

In addition, prior to the Closing, subject to certain agreed exceptions or except as consented to in writing by Mizuho Americas (which consent may not be unreasonably withheld, conditioned or delayed), Greenhill has agreed not to and has agreed not to permit its subsidiaries to:

Greenhill has agreed, as promptly as reasonably practicable after the filing of this proxy statement with the SEC and subject to applicable law, Greenhill’s certificate of incorporation and bylaws, and the rules of NYSE, to (i) establish a record date for, duly call, give notice of, convene and hold a meeting of its stockholders for the purpose of obtaining the Stockholder Approval and (ii) commence mailing the proxy statement to Greenhill stockholders as promptly as reasonably practicable after (and in any event, unless otherwise agreed by Greenhill and Mizuho Americas, within 10 business days after) either (A) the date that is 10 days after filing the proxy statement in preliminary form if, prior to such date, the SEC staff does not provide comments or indicates that it does not plan to provide comments or (B) being informed by the SEC staff that it has no further comments on the proxy statement. The Special Meeting constitutes that required meeting of the Greenhill stockholders.

Subject to the ability of the Board of Directors to make an Adverse Recommendation Change, as described in the section of this proxy statement entitled “The Merger Agreement—Adverse Recommendation Change; Certain Prohibited Actions,” the Board of Directors is required to recommend to Greenhill stockholders the adoption of the Merger Agreement (which we refer to as the “Board Recommendation”) and Greenhill is required to include the Board Recommendation in this proxy statement and use reasonable best efforts to solicit votes of the Greenhill stockholders in favor of obtaining the Stockholder Approval.

Under the terms of the Merger Agreement, Greenhill may adjourn or postpone the Greenhill stockholders’ meeting (A) with Mizuho Americas’ consent or (B) without Mizuho Americas’ consent (i) for no more than 30 days after the date on which the stockholders’ meeting was (or was required to be) originally scheduled, if Greenhill is unable to obtain a quorum of its stockholders at such time, to the extent (and only to the extent) necessary in order to obtain a quorum of its stockholders and provided that Greenhill uses its reasonable best efforts to obtain such a quorum as promptly as practicable thereafter, (ii) for no more than 10 business days, if there are not sufficient affirmative votes (either in person or by proxy) at such meeting to adopt the Merger Agreement or to allow reasonable time for the solicitation of proxies for purposes of obtaining the Stockholder Approval, (iii) for no more than 10 business days, if the Board of Directors has determined in good faith (after consultation with outside legal counsel) that such delay is required by applicable law to comply with comments made by the SEC with respect to the proxy statement or to allow reasonable additional time for the filing or mailing of any supplemental or amended disclosure that Greenhill has determined, after consultation with outside legal counsel, is reasonably likely to be required under applicable law and for such supplemental or amended disclosure to be disseminated and reviewed by stockholders of Greenhill prior to the stockholders’ meeting, or (iv) for no more than 10 business days, if Greenhill is required to do so by a court of competent jurisdiction in connection with any Transaction Litigation. Greenhill must, at the instruction of Mizuho Americas, postpone or adjourn the stockholders’ meeting if there are not sufficient affirmative votes in person or by proxy at such meeting to adopt the Merger Agreement to allow reasonable time for the solicitation of proxies for purposes of obtaining the Stockholder Approval.

Unless the Merger Agreement is validly terminated in accordance with its terms, Greenhill must submit the Merger Agreement to its stockholders for adoption at the Special Meeting even if the Board of Directors has made an Adverse Recommendation Change.

For purposes of the Merger Agreement, an “Adverse Recommendation Change” refers to (1) any withdrawal, qualification or modification in a manner adverse to Mizuho Americas, or public proposal to withdraw, qualify or modify in a manner adverse to Mizuho Americas, the Board Recommendation, (2) any failure to include the Board Recommendation in this proxy statement or (3) if any Takeover Proposal that is structured as a tender offer or exchange offer for the outstanding shares of Greenhill common stock is commenced pursuant to Rule 14d-2 under the Exchange Act (other than by Mizuho Americas or an affiliate of Mizuho Americas), any failure to recommend, within 10 business days after such commencement, against acceptance by Greenhill’s stockholders of such tender offer or exchange offer.

Greenhill was required to, and was required to cause its subsidiaries and its and their respective directors, officers and employees to, and to use its reasonable best efforts to cause its other representatives to, immediately cease and cause to be terminated, and must not authorize or knowingly permit any representative to continue, any and all existing activities, discussions or negotiations with any third party conducted prior to the date of the Merger Agreement with respect to any possible Takeover Proposal (as defined below). Promptly following the execution of the Merger Agreement, Greenhill was required to (i) request each person and its representatives (other than Mizuho Americas and its representatives) that has, prior to the date of the Merger Agreement, executed a confidentiality agreement in connection with its consideration of making a Takeover Proposal promptly destroy or return to Greenhill all nonpublic information furnished to that person by or on behalf of Greenhill or any of its subsidiaries prior to the date of the Merger Agreement and (ii) immediately terminate all physical and electronic data room access for such persons and their representatives to diligence or other information regarding Greenhill or its subsidiaries. In addition, Greenhill must not modify, amend or terminate, or waive, release or assign, any provisions of any confidentiality or explicit or implicit standstill obligations (or any similar agreement) to which Greenhill or its subsidiaries is a party relating to any Takeover Proposal and must enforce the provisions of any such agreement, except that Greenhill is permitted on a confidential non-public basis to release or waive any such standstill obligations or similar agreements solely to the extent necessary to permit the relevant party thereto to submit a Takeover Proposal to the Board of Directors on a confidential non-public basis if the Board of Directors determines in good faith that the failure to do so would be inconsistent with its fiduciary duties under applicable law. Greenhill will provide written notice to Mizuho Americas of the release or waiver of any standstill or similar agreements by Greenhill reasonably promptly following, but in any event within 24 hours of, such release or waiver, including disclosure of the identities of the parties thereto and the circumstances relating thereto.

Under the terms of the Merger Agreement, Greenhill may not, and must cause its subsidiaries and its and their respective directors, officers and employees not to, and will not authorize or knowingly permit its other representatives to, and will direct and use its reasonable best efforts to cause each of its other representatives not to, directly or indirectly, (i) solicit, initiate, propose or knowingly encourage, knowingly induce or knowingly facilitate any inquiries or the making of any proposal that would reasonably be expected to lead to a Takeover Proposal, (ii) enter into, continue or otherwise participate in any discussions or negotiations regarding, or furnish to any person (or any representative thereof) any information (or access thereto), in any such case in connection with or for the purpose of facilitating, any Takeover Proposal, (iii) except with respect to a Permitted Confidentiality Agreement (as defined below), execute or enter into any letter of intent, memorandum of understanding, agreement in principle, acquisition agreement, merger agreement, option agreement, joint venture agreement, partnership agreement or other agreement (which we refer to as an “Acquisition Agreement”) relating to any Takeover Proposal, (iv) approve, authorize, agree or publicly announce any intention to do any of the foregoing or (v) approve any transaction under, or any third party becoming an “interested stockholder” under, Section 203 of the DGCL, or any “significant business transaction.”

However, at any time prior to obtaining the Stockholder Approval, (i) in response to a written unsolicited Takeover Proposal, (ii) from a third party that the Board of Directors determines in good faith to (a) be bona fide and (b) constitute, or would reasonably be expected to result in, a Superior Proposal (as defined below), and (iii) which Takeover Proposal did not result from a material breach of the no-solicitation provisions of the Merger Agreement, then Greenhill may (A) furnish information with respect to Greenhill and its subsidiaries to

the person making such Takeover Proposal (and its representatives and financing sources) pursuant to a confidentiality agreement that contains terms that are no less restrictive on such person in all material respects than those contained in the confidentiality agreement between Greenhill and Mizuho Americas and that does not contain any exclusivity provision or other term that would restrict, in any manner, Greenhill’s ability to consummate the transactions contemplated by the Merger Agreement or to comply with its disclosure obligations to Mizuho Americas pursuant to the Merger Agreement (which we refer to as a “Permitted Confidentiality Agreement”) (provided, that such information may only be so furnished if it has previously been provided, or is substantially concurrently provided, to Mizuho Americas) and (B) participate in discussions or negotiations with, and only with, the person making such Takeover Proposal (and its representatives and financing sources) regarding such Takeover Proposal.

For purposes of the Merger Agreement, a “Takeover Proposal” means any proposal or offer from any person or group of persons (other than, in each case, Mizuho Americas or Merger Sub or any of their affiliates), relating to a transaction or a series of related transactions (other than the transactions contemplated by the Merger Agreement), providing for any merger, consolidation, business combination, recapitalization, reorganization, share exchange, or similar transaction involving Greenhill or any of its subsidiaries, in each case, involving any direct or indirect acquisition (including by way of any of the foregoing, a tender offer, exchange offer or any other similar transaction), of (A) tangible or intangible assets or businesses that constitute or represent 20% or more of the total consolidated revenue, net income, or total consolidated assets, in each case, of Greenhill and its subsidiaries, taken as a whole (including equity securities of subsidiaries), or (B) 20% or more of the issued and outstanding shares of Greenhill common stock or of any class of equity or voting interests in Greenhill or of the surviving entity in a merger or the resulting direct or indirect parent of Greenhill or such surviving entity.

For purposes of the Merger Agreement, a “Superior Proposal” means any bona fide written Takeover Proposal that did not result from a material breach of Greenhill’s no-solicitation covenants (with the percentages set forth in the definition thereof changed from 20% to 50%) that the that the Board of Directors determines in good faith (after consultation with outside legal counsel and a financial advisor of nationally recognized reputation) (A) is on terms that are more favorable from a financial point of view to the Greenhill stockholders than the transactions contemplated by the Merger Agreement, taking into account financial, legal, regulatory, financing, certainty and timing of consummation and all of the other terms and conditions of such proposal and the Merger Agreement (including any changes to the terms of the Merger Agreement proposed by Mizuho Americas to Greenhill prior to the expiration of the applicable time periods provided for in the Merger Agreement in response to such Superior Proposal or otherwise) and (B) is reasonably likely to be completed in accordance with its terms.

Greenhill must as promptly as practicable and in any event within 24 hours after it has knowledge of the receipt thereof, advise Mizuho Americas, orally and in writing, in the event it receives (i) any Takeover Proposal or (ii) any inquiry or request for information that contemplates or is in furtherance of a Takeover Proposal, and, in each case, must include in the notice the terms and conditions of such Takeover Proposal, request or inquiry (including any subsequent amendment or other modification to such terms and conditions) and the identity of the person or persons making any such Takeover Proposal, request or inquiry. Commencing upon the provision of any notice referred to above, Greenhill (or its outside counsel) must (A) keep Mizuho Americas (or its outside counsel) reasonably informed on a reasonably current basis regarding the status and terms of discussions and negotiations relating to any such Takeover Proposal, request or inquiry and (B) as promptly as practicable (and in any event within 24 hours following the receipt or delivery thereof), provide Mizuho Americas (or its outside legal counsel) with unredacted copies of all writings or media (whether or not electronic) containing any terms or conditions of any proposals or proposed transaction agreements (including all relevant schedules, appendices, annexes, exhibits and other attachments thereto) relating to any Takeover Proposal and any financing commitments relating thereto.

Except as described below, neither the Board of Directors nor any of its committees may:

Notwithstanding the foregoing, at any time prior to obtaining the Stockholder Approval, the Board of Directors may, in response to a Superior Proposal not resulting from a material breach by Greenhill of its no-solicitation covenants, (1) make an Adverse Recommendation Change or (2) cause Greenhill to terminate the Merger Agreement to enter into an Acquisition Agreement with respect to such Superior Proposal, or resolve or agree to take any such action, in each case, if and only if all of the following conditions are satisfied:

In addition, at any time prior to obtaining the Stockholder Approval, the Board of Directors may, in response to an Intervening Event (as defined below), make an Adverse Recommendation Change, if and only if all of the following conditions are satisfied:

In the event of any revisions to a Superior Proposal or any material change to the facts and circumstances relevant to an Intervening Event, Greenhill will be required to deliver a new Superior Proposal Notice or Intervening Event Notice, as applicable, and to again comply with the requirements set forth above with respect to the revised Superior Proposal or the modified Intervening Event (after giving effect to the changed facts and circumstances) (except that the new negotiation period will expire on the later to occur of (x) two business days and (y) the expiration of the original four business day period).

For purposes of the Merger Agreement, an “Intervening Event” means any event, development or change in circumstances that was not known to the Board of Directors, or the consequences of which were not reasonably foreseeable, as of the date of the Merger Agreement, which event, change or development becomes known to the Board of Directors prior to obtaining the Stockholder Approval. However, in no event will any of the following events, changes or developments constitute an Intervening Event: (A) the receipt, existence or terms of a Takeover Proposal or (B) any change in the price or trading volume of the Greenhill common stock or any other securities of Greenhill (provided, that the underlying causes of such changes may constitute or be taken into account in determining whether there has been an Intervening Event).

Nothing in the Merger Agreement prohibits Greenhill from (i) taking and disclosing to its stockholders a position contemplated by Rule 14d-9 and Rule 14e-2(a) promulgated under the Exchange Act or (ii) making any disclosure to its stockholders if the Board of Directors determines in good faith that failure to so disclose would be inconsistent with the directors’ fiduciary duties under applicable law. Nothing in this paragraph, however, will permit the Board of Directors to make an Adverse Recommendation Change, adopt or approve any Takeover Proposal or recommend, declare advisable or propose to recommend or declare advisable the approval or adoption of any Takeover Proposal or cause or permit Greenhill to enter into any Acquisition Agreement constituting or related to, or which is intended to or would reasonably be expected to lead to, any Takeover Proposal (other than a Permitted Confidentiality Agreement as described above), except to the extent permitted by the terms of the Merger Agreement described above. Any public disclosure by Greenhill permitted by this paragraph relating to any Takeover Proposal must state that the Board Recommendation continues to be in effect unless, prior to the time of such public disclosure, an Adverse Recommendation Change has been made (and has not been rescinded) in compliance with of the no-solicitation provisions of the Merger Agreement.

From and after the Closing, Mizuho Americas will cause Greenhill and its subsidiaries to honor all Greenhill benefit plans in accordance with their terms as in effect immediately before the Closing (it being understood that Mizuho Americas or its affiliates will not be prohibited from amending, modifying, replacing or terminating such arrangements in accordance with their terms).

For the period beginning on the Closing and ending on the first anniversary of the Closing, while the applicable employee remains employed by Mizuho Americas or one of its affiliates following the Effective Time, Mizuho Americas will provide, or will cause one of its affiliates to provide, to employees of Greenhill who remain employed after the Closing (each of which we refer to as a “Continuing Employee”):

In addition, any Continuing Employee who is terminated on or following the Closing Date will be provided with severance benefits as set forth in the confidential disclosure schedules to the Merger Agreement, or such greater benefits as may be required by applicable law.

The Chairman and Chief Executive Officer of Greenhill as of immediately prior to the Effective Time will recommend to Mizuho Americas the annual bonus amount to be paid to each Continuing Employee for the period beginning on January 1, 2023 and ending on March 31, 2024. Mizuho Americas will consider such recommendations from the Chairman and Chief Executive Officer in good faith and will, to the extent not

previously paid prior to the Closing or required to be paid on an earlier date in accordance with the applicable Greenhill benefit plan, pay the actual earned amount of such bonus to each Continuing Employee who remains employed in April 2024 in accordance with Mizuho Americas’ standard year-end payment cycle and, to the extent applicable, subject to Mizuho Americas’ applicable deferral schedule (with any deferred amounts to be credited with interest benchmarked to the prevailing consumer price index in accordance with Mizuho Americas’ deferred bonus plan and on a basis no less favorable than as applicable to similarly situated employees of Mizuho Americas or its applicable subsidiaries) and Section 409A of the Code.

Mizuho Americas or its applicable affiliates will give Continuing Employees full credit for all purposes, including eligibility to participate, vesting and level of benefits (but not benefit accrual under defined benefit plans, level of benefits under Mizuho Americas’ severance plans or under the Mizuho Americas 401(k) Plan (as defined below)) under the employee benefit plans or arrangements (excluding all defined benefit pension, post-employment health or welfare benefit plans and arrangements) maintained by Mizuho Americas or its affiliates and in which such Continuing Employees participate after the Closing, for such Continuing Employees’ service prior to the Closing with Greenhill or any of its subsidiaries, to the same extent recognized by Greenhill and its subsidiaries prior to the Closing (provided, that for Continuing Employees located in any jurisdiction other than the United States, continued participation in the Greenhill benefit plans on the same basis as in effect immediately prior to the Effective Time will be deemed to satisfy the foregoing), provided that effective immediately and automatically on the third anniversary of the Closing Date, Mizuho Americas and its affiliates will give credit to each Continuing Employee for such employees’ service prior to the Closing with Greenhill or any of its subsidiaries, to the same extent recognized by Greenhill and its subsidiaries, for purposes of determining “Retirement” under Mizuho Americas’ deferred bonus plan or any successor or replacement plan.

With respect to any welfare plan maintained by Mizuho Americas in which Continuing Employees are eligible to participate after the Closing, Mizuho Americas will, and will cause the Surviving Corporation to, waive all limitations as to preexisting conditions and exclusions with respect to participation and coverage requirements applicable to such employees to the extent such conditions and exclusions were satisfied or did not apply to such employees under the welfare plans of Greenhill and its subsidiaries prior to the Closing and provide Continuing Employees with credit for any co-payments and deductibles paid prior to the Closing in satisfying any analogous deductible or out-of-pocket requirements to the same extent recognized by Greenhill or its subsidiaries prior to the Closing.

The Board of Directors (or the appropriate committee thereof) will take actions necessary to terminate the Greenhill 401(k) plan (which we refer to as the “401(k) Plan”), such termination to be effective as of the day prior to the Closing Date and contingent upon the occurrence of the Effective Time unless Mizuho Americas provides written notice to Greenhill no later than 10 business days prior to the Effective Time that the 401(k) Plan should not be terminated. Unless Mizuho Americas provides such written notice to the Company, no later than two days prior to the Closing Date, Greenhill will provide Mizuho Americas with evidence that the 401(k) Plan has been terminated pursuant to resolutions of the Board of Directors (effective as of the day immediately preceding the Closing Date), the form and substance of which will be subject to reasonable review and comment by Mizuho Americas. Mizuho Americas will, effective as of the Closing Date, offer participation in its tax qualified defined contribution plan (the “Mizuho Americas 401(k) Plan”) to each Continuing Employee who was an active participant in the 401(k) Plan as of the date of its termination and who satisfies the eligibility requirements of the Mizuho Americas 401(k) Plan. If elected by such Continuing Employee in accordance with applicable law, Mizuho Americas will permit the Mizuho Americas 401(k) Plan to, following the Closing Date, accept a “direct rollover” to such Mizuho Americas 401(k) Plan of the account balances (including any participant loans) of such Continuing Employee.

The indemnification and exculpation rights, and related rights to advancement of expenses, of any current or former director, officer or employee of Greenhill or its subsidiaries for acts or omissions occurring at or prior to the Effective Time, provided for in their respective organizational documents or other agreement of Greenhill existing as of the date of the Merger Agreement, will be assumed by the Surviving Corporation in the Merger, and will survive the Merger and will continue in full force and effect in accordance with their terms, and Mizuho Americas will cause the Surviving Corporation to comply with and honor the foregoing obligations. The Merger Agreement requires the Surviving Corporation to indemnify any person who is or was prior to the Effective Time an officer or director of Greenhill or any of its subsidiaries or who was as of the date of the Merger Agreement,

or who thereafter commences prior to the Effective Time, serving at the request of Greenhill or any of its subsidiaries as a director or officer of another person (who we refer to as the “Indemnified Parties”) for a period of six years after the Closing against claims, losses, liabilities, damages, judgments, fines, amounts paid in settlement and fees, costs and expenses, including attorneys’ fees and disbursements, incurred in connection with any actual or threatened legal proceeding (including with respect to matters existing or occurring or alleged to occur at or prior to the Effective Time (including the Merger Agreement and the transactions and actions contemplated by the Merger Agreement)) arising from their service as a director or officer of Greenhill or any of its subsidiaries prior to the Effective Time or as a director or officer of another person at the request of Greenhill or any of its subsidiaries as of the date of the Merger Agreement or prior to the Effective Time. In the event of any such legal proceeding, (i) each Indemnified Party will be entitled to advancement of expenses incurred in the defense of any such legal proceeding from the Surviving Corporation within 15 business days of receipt by the Surviving Corporation from the Indemnified Party of a request therefor accompanied by reasonable supporting documentation; provided, that any person to whom expenses are advanced provides an undertaking, if and only to the extent required by the DGCL or the Surviving Corporation’s certificate of incorporation or bylaws, to repay such advances if it is ultimately determined by final adjudication that such person is not entitled to indemnification, and (ii) the Surviving Corporation will cooperate in the defense of any such matter.

In the event that the Surviving Corporation or any of its successors or assigns (i) consolidates with or merges into any other person and is not the continuing or surviving corporation or entity of such consolidation or merger or (ii) transfers or conveys all or substantially all its properties and assets to any person, or if Mizuho Americas dissolves the Surviving Corporation, then, and in each such case, Mizuho Americas will cause proper provision to be made so that the successors and assigns of the Surviving Corporation assume the indemnification obligations set forth in the Merger Agreement.

Mizuho Americas must obtain, or cause to be obtained, at or prior to the Effective Time, a “tail” insurance policy with a claims period of six years from the Effective Time, with respect to directors’ and officers’ liability insurance covering each person currently covered by Greenhill’s directors’ and officers’ liability insurance policy for acts or omissions occurring prior to the Effective Time, on terms that are no less favorable than those of such policy of Greenhill in effect as of the date of the Merger Agreement, which insurance will, prior to the Closing, be in effect and prepaid for such six-year period; provided, that in no event will Mizuho Americas or the Surviving Corporation be required to pay, with respect to the entire six-year period following the Effective Time, premiums for insurance which in the aggregate exceed 300% of the aggregate premiums paid by Greenhill for coverage for the most recent one-year period for which Greenhill obtained such coverage, but in any such case, Mizuho Americas will be obligated to provide such coverage with respect to the entire six-year period following the Effective Time as may be obtained for such 300% amount.

The Merger Agreement provides that Greenhill will control the defense of any Transaction Litigation, and Greenhill has agreed to (i) promptly notify Mizuho Americas in writing of any such Transaction Litigation, (ii) give Mizuho Americas the opportunity to participate in the defense and settlement of any such Transaction Litigation, and (iii) keep Mizuho Americas promptly informed with respect to such Transaction Litigation. Greenhill may not compromise or settle any Transaction Litigation without Mizuho Americas’ prior written consent (which consent may not be unreasonably withheld, conditioned, or delayed).

Subject to the terms and conditions of the Merger Agreement, each party has agreed to use and to cause its respective affiliates to use reasonable best efforts to take, or cause to be taken, all actions and to do, or cause to be done, all things necessary, proper or advisable under applicable law to obtain the Requisite Regulatory Approvals in order to consummate the Merger and the other transactions contemplated by the Merger Agreement as soon as practicable, and in any event no later than the Termination Date.

Specifically, in furtherance of and without limiting the generality of the above:

However, none of Mizuho Americas, Merger Sub or any of their respective subsidiaries is required to, and Greenhill may not, without the prior written consent of Mizuho Americas, take any of the following actions, or commit to take any of the following actions, or agree to any condition or limitation with respect to Mizuho Americas, its affiliates, Greenhill, its affiliates or their respective assets, categories of assets, businesses, relationships, contractual rights, obligations or arrangements, and any intellectual property rights thereto or embodied therein: (A) proposing, negotiating, committing to and effecting, by consent decree, hold separate order or otherwise, the sale, divestiture, disposition, license or other disposition of any subsidiaries, operations, divisions, businesses, product lines, contracts, customers or assets of Mizuho Americas or any of its affiliates (including Greenhill or any of its subsidiaries), (B) taking or committing to take such other actions that may limit or impact Mizuho Americas’ or any of its affiliates’ (including Greenhill’s or any of its subsidiaries’) freedom of action with respect to, or its ability to retain, any of Mizuho Americas’ or any of its affiliates’ (including Greenhill’s or any of its subsidiaries’) operations, divisions, businesses, product lines, contracts, customers or assets, (C) entering into any orders, settlements, undertakings, contracts, consent decrees, stipulations or other agreements to effectuate any of the foregoing or in order to vacate, lift, reverse, overturn, settle or otherwise resolve any order that prevents, prohibits, restricts or delays the consummation of the Merger and the other

transactions contemplated by the Merger Agreement, in any case, that may be issued by any court or other governmental entity and (D) creating, terminating or divesting relationships, contractual rights or obligations of Greenhill, Mizuho Americas or their respective affiliates. In addition, none of Mizuho Americas, Greenhill or any of their respective affiliates will be required to take or commit to take any action, or agree to any condition or limitation, in connection with obtaining the Requisite Regulatory Approvals that is not conditioned on the consummation of the Merger.

Pursuant to the Merger Agreement, neither Mizuho Americas nor Merger Sub may, nor may they permit their respective affiliates to, acquire or agree to acquire any rights, assets, business, person or division thereof (through acquisition, license, joint venture, collaboration or otherwise), if such acquisition would reasonably be expected to materially increase the risk of not obtaining, or the risk of materially delaying the obtaining of, the Requisite Regulatory Approvals.

Each party has also agreed to use and to cause its respective affiliates to use reasonable best efforts to obtain all necessary approvals, consents or waivers and deliver all notifications pursuant to certain specified contracts in connection with the Merger Agreement and the consummation of the Merger. However, Greenhill and its subsidiaries will not have any obligation to make any payments or incur any liability or offer or grant any concession or accommodation (financial or otherwise) or commence or participate in any legal proceeding in order to obtain any such approvals, consents or waivers, and Greenhill and its subsidiaries will not have any liability whatsoever to Mizuho Americas or any of its affiliates arising out of or relating to the failure to obtain any such approvals, consents or waivers.

Under the Merger Agreement, Mizuho Americas has agreed that, in the event that (a) the Closing has not occurred by March 12, 2024 (which we refer to as the “Refinancing Trigger Date”), (b) the stated maturity date for the term loans under the Company Credit Agreement (which we refer to as the “Company Term Loans”) has not been extended to at least April 12, 2025, and (c) Greenhill delivers a written request to Mizuho Americas, Mizuho Americas will provide, or cause to be provided, to Greenhill on (or if requested by Greenhill, after) the Refinancing Trigger Date, a new term loan credit facility (which we refer to as the “Mizuho Americas Replacement Credit Facility”), (i) in an aggregate principal amount equal to the aggregate principal amount of the Company Term Loans outstanding prior to the making of the Mizuho Americas Replacement Credit Facility, plus accrued and unpaid interest and premium thereon and (ii) on terms substantially the same as the terms and conditions applicable to the Company Term Loans as in effect immediately prior to the making of the Mizuho Americas Replacement Credit Facility, except that (A) such new term loans will have (1) an interest rate no less favorable to Greenhill than that available in the market for a credit facility of similar type and amount to a borrower of similar creditworthiness to Greenhill at such time, (2) a stated maturity date no earlier than April 12, 2027, and (3) conditions to drawing that do not include a bringdown of representations, an absence of default or event of default, an absence of material adverse effect, a requirement to deliver financial statements, or a minimum required equity investment; (B) the proceeds of the Mizuho Americas Replacement Credit Facility will be used to refinance the term loans outstanding under the Company Credit Agreement, to pay accrued and unpaid interest and premium thereon and to pay any fees and expenses incurred by Greenhill and its subsidiaries in connection therewith; and (C) Greenhill and its subsidiaries will not be required to pay any commitment, arrangement, upfront or similar fee or any other compensation or fees of any kind to Mizuho Americas or any of its affiliates in connection with the negotiation, entry into or making of the Mizuho Americas Replacement Credit Facility. Greenhill has agreed that if it requests the Mizuho Americas Replacement Credit Facility, Greenhill and its subsidiaries will reasonably cooperate with Mizuho Americas in the provision of the Mizuho Americas Replacement Credit Facility, including negotiating the definitive documentation relating to the Mizuho Americas Replacement Credit Facility in good faith.

In addition, to the extent that the Company Credit Agreement is then outstanding and has not been refinanced by the Mizuho Americas Replacement Credit Facility, Greenhill will use commercially reasonable efforts to deliver to Mizuho Americas no less than one business day prior to the Closing customary payoff letters in connection with the repayment by Mizuho Americas at the Effective Time of the funded indebtedness of Greenhill and its subsidiaries under the Company Credit Agreement, which payoff letters will (i) acknowledge the aggregate principal amount and accrued and unpaid interest outstanding in respect of such indebtedness as of the Effective Time, and (ii) provide for the termination of all agreements relating to such indebtedness, subject to customary exceptions (including any provisions that expressly survive repayment in full), and the release and

termination of all liens securing such indebtedness and all guarantees by Greenhill or any of its subsidiaries of such indebtedness, in each case, upon receipt of payment in full (from funds provided by Mizuho Americas) of the applicable payoff amount specified therein in accordance therewith (including the replacement or cash collateralization by Mizuho Americas of any letters of credit outstanding thereunder). Greenhill will use commercially reasonable efforts to provide all required notices in connection with the repayment and termination of such indebtedness as of the Effective Time (or obtain waivers of the requirement to provide such notice); except that in no event will Greenhill be required to give any such notice that is not conditioned on the occurrence of the Closing.

The Merger Agreement contains additional covenants and agreements relating to, among other things:

The respective obligations of each party to effect the Merger are subject to the satisfaction or (to the extent permitted by applicable law) waiver, on or prior to the Closing Date, of each of the following conditions:

In addition, the respective obligations of Mizuho Americas and Merger Sub to effect the Merger are subject to the satisfaction or (to the extent permitted by applicable law) waiver by Mizuho Americas and Merger Sub, on or prior to Closing Date, of each of the following additional conditions:

In addition, the obligation of Greenhill to effect the Merger is subject to the satisfaction or (to the extent permitted by applicable law) waiver, on or prior to the Closing Date, of each of the following additional conditions:

None of Greenhill, Mizuho Americas or Merger Sub may rely on the failure of any of the foregoing conditions to be satisfied if such failure was caused by such party’s failure to use reasonable best efforts to consummate the Merger and the other transactions contemplated by the Merger Agreement, as required by and subject to the obligations set forth in the section of this proxy statement entitled “The Merger Agreement—Approvals and Related Matters,” or by such party’s breach of any other provision of the Merger Agreement.

The Merger Agreement may be terminated by mutual written consent of Greenhill and Mizuho Americas at any time prior to the Effective Time. In addition, the Merger Agreement may be terminated as follows (upon written notice to the non-terminating specifying the provision of the Merger Agreement pursuant to which the termination is effected):

If the Merger Agreement is terminated as described above, the Merger Agreement will have no effect, without any liability or obligation on the part of any party, and each party’s rights and obligations will cease, subject to certain exceptions, including that:

Mizuho Americas will be entitled to receive a termination fee of $15,380,000 from Greenhill (which we refer to as the “Company Termination Fee”) if the Merger Agreement is validly terminated:

If the termination is made pursuant to the first bullet above, the Company Termination Fee must be paid within two business days of the earlier of (i) the date of entry into the Acquisition Agreement with respect to the Takeover Proposal or (ii) the date of consummation of the transactions contemplated by the Takeover Proposal. If the termination is made pursuant to the second bullet above, the Company Termination Fee must be paid within two business days following termination. If the Merger Agreement is terminated pursuant to the third bullet above, the Company Termination Fee must be paid on the date of termination.

Greenhill will be entitled to receive a termination fee of $38,500,000 from Mizuho Americas (which we refer to as the “Mizuho Americas Termination Fee”) if the Merger Agreement is validly terminated:

If the Merger Agreement is terminated in these circumstances, the Mizuho Americas Termination Fee must be paid by Mizuho Americas within two business days following termination.

If either Greenhill or Mizuho Americas fails to promptly pay the Company Termination Fee or Mizuho Americas Termination Fee, as applicable, and either Greenhill or Mizuho Americas, as applicable, commences a legal proceeding that results in a judgment against the other party for the payment of the applicable termination fee, the payor party must pay the payee party its reasonable costs and expenses (including attorneys’ fees and expenses) in connection with such legal proceeding and any appeal related thereto, together with interest on such amount at the prime rate as published in The Wall Street Journal in effect on the date such payment was required to be made.

Without limiting the parties’ rights to pursue specific performance, in the event that the Merger Agreement is terminated under circumstances where a termination fee is payable and is so paid, the payment of the applicable termination fee to the party entitled to receive that payment (together with any collection expenses described in the paragraph above) will be the sole and exclusive remedy of that party and its subsidiaries and its former, current or future partners, stockholders, managers, members, affiliates and representatives, other than for fraud or Willful Breach. Neither Greenhill nor Mizuho Americas will be required to pay the Company Termination Fee or the Mizuho Americas Termination Fee, respectively, on more than one occasion.

The parties have agreed in the Merger Agreement that irreparable damage would occur in the event that any of the provisions of the Merger Agreement were not performed in accordance with their specific terms or were otherwise breached. The parties have agreed that the parties will be entitled to an injunction or injunctions to prevent breaches of the Merger Agreement and to enforce specifically the terms and provisions of the Merger Agreement in addition to any other remedy to which they are entitled at law or in equity. The parties have further agreed not to assert that a remedy of specific enforcement is unenforceable, invalid, contrary to law or inequitable for any reason, nor to assert that a remedy of monetary damages would provide an adequate remedy for any such breach. In the event any party brings any proceeding to enforce specifically the performance of the terms and provisions of the Merger Agreement prior to the Closing, the Termination Date will automatically be extended by (i) the amount of time during which such proceeding is pending, plus 20 business days, or (ii) such other time period established by the court presiding over such action, claim, complaint, suit, action or other proceeding.

Except as otherwise provided in the Merger Agreement, whether or not the Merger is consummated, all fees and expenses incurred in connection with the Merger Agreement, the Merger and the other transactions contemplated by the Merger Agreement will be paid by the party incurring such fees or expenses.

The Merger Agreement may be amended by the parties at any time by execution of an instrument in writing signed on behalf of each of Mizuho Americas, Merger Sub and Greenhill, except that after the Stockholder Approval has been obtained, no amendment may be made to the Merger Agreement that by law requires the approval of the Greenhill stockholders without such further approval of the Greenhill stockholders.

At any time prior to the Effective Time, any party may (i) extend the time for the performance of any of the obligations or other acts of the other parties; (ii) waive any inaccuracy in any representation or warranty of the other party in the Merger Agreement or in any document delivered pursuant to the Merger Agreement; and/or (iii) waive compliance with any agreement or condition contained in the Merger Agreement (except that (A) after the Stockholder Approval has been obtained, there may be made no waiver that by law requires further approval by the Greenhill stockholders without the further approval of such stockholders and (B) any such extension or waiver in clauses (i) through (iii) will only be valid if made in a written instrument duly executed and delivered by the party against whom such extension or waiver is to be valid). The failure or delay by any of Greenhill, Mizuho Americas or Merger Sub to assert any of its rights under the Merger Agreement or otherwise will not constitute a waiver of such rights nor shall any single or partial exercise by any such party of any of its rights under the Merger Agreement preclude any other or further exercise of such rights or any other rights under the Merger Agreement.

The Merger Agreement is not intended to confer upon any person other than the parties thereto (and their respective successors and assigns) any rights (legal, equitable or otherwise) or remedies, whether as third-party beneficiaries or otherwise, except for (i) the right of the Greenhill stockholders to receive the Merger Consideration following the Effective Time in accordance with the terms of the Merger Agreement, (ii) the right of the holders of RSUs, PSUs or Deferred Cash Awards to receive the consideration set forth in the Merger Agreement and (iii) the Indemnified Parties who have indemnification rights as described in the section entitled “The Merger Agreement— Directors’ and Officers’ Indemnification and Insurance” of this proxy statement.

The Merger Agreement will be governed by, and construed in accordance with, the laws of the State of Delaware, regardless of the laws that might otherwise govern under applicable principles of conflicts of laws thereof. Each of Greenhill, Mizuho Americas and Merger Sub has agreed that it will bring any suit, action or other proceeding relating to the Merger Agreement or the transactions contemplated thereby exclusively in the Delaware Court of Chancery or, only if such court declines to accept jurisdiction over a particular matter, then in the United States District Court for the District of Delaware or, if jurisdiction is not then available in the United States District Court for the District of Delaware (but only in such event), then in any Delaware state court sitting in New Castle County and any appellate court from any of such courts for the purposes of any suit, action or other legal proceeding arising out of the Merger Agreement, the Merger or any other transaction contemplated by the Merger Agreement (and agrees that no such action, suit or other legal proceeding relating to the Merger Agreement will be brought by it or any of its subsidiaries except in such courts). Each of the parties agreed that, to the fullest extent permitted by applicable law, service of any process, summons, notice or document by U.S. registered mail to such person’s respective address set forth in the Merger Agreement will be effective service of process for any action, suit or other legal proceeding in the courts set forth above with respect to any matters to which it has submitted to jurisdiction as set forth above in the immediately preceding sentence. Each of the parties has agreed to waive (and agreed not to plead or claim), any objection to the laying of venue of any proceeding arising out of the Merger Agreement, the Merger or any of the other transactions contemplated by the Merger Agreement in the courts described above, or that any such proceeding brought in any such court has been brought in an inconvenient forum.

The parties have agreed to irrevocably and unconditionally waive, to the fullest extent permitted by applicable law, all rights to trial by jury in respect of any suit, action, or other proceeding directly or indirectly arising out of, under or in connection with the Merger Agreement.

The following summarizes the provisions of the Voting Agreement. The descriptions of the Voting Agreement in this summary and elsewhere in this proxy statement are not complete and are qualified in their entirety by reference to the Voting Agreement, a copy of which is attached to this proxy statement as Annex B and incorporated into this proxy statement by reference.

Concurrently with the execution and delivery of the Merger Agreement, Scott L. Bok and the other Specified Stockholders entered into a Voting Agreement with Mizuho Americas and Merger Sub. Pursuant to the Voting Agreement, the Specified Stockholders have agreed to vote all shares of Greenhill common stock owned by them (i) in favor of (a) the adoption of the Merger Agreement and the approval of the transactions contemplated thereby and (b) the approval of any proposal to adjourn the Special Meeting to a later date, if there are not sufficient affirmative votes (in person or by proxy) to obtain the Stockholder Approval on the date on which the Special Meeting is held and (ii) against (a) any action or agreement that would reasonably be expected to result in a breach by Greenhill of the Merger Agreement or result in any condition described in the section entitled “The Merger Agreement— Conditions to the Closing of the Merger” of this proxy statement not being satisfied on a timely basis and (b) any Takeover Proposal or approval of any other proposal, transaction, agreement or action, made in opposition to or in competition with, or that would reasonably be expected to prevent, delay or impede the consummation of, the Merger Agreement, the Merger or any other transactions contemplated thereby. The Voting Agreement includes customary transfer restrictions, subject to certain exceptions.

The Voting Agreement terminates upon the earlier to occur of (i) the Effective Time, (ii) the termination of the Merger Agreement in accordance with its terms and (iii) the date on which any amendment to the Merger Agreement is executed, or any waiver of Greenhill’s rights under the Merger Agreement is granted, in each case, without the Specified Stockholders’ prior written consent, that (a) diminishes (in any amount) the Merger Consideration to be received by the Greenhill stockholders, (b) changes the form of Merger Consideration payable to the Greenhill stockholders or (c) modifies the Termination Date or imposes any additional conditions or obligations that would reasonably be expected to prevent or impede the consummation of the Merger by the Termination Date.

As of the Record Date, the Specified Stockholders held in the aggregate 2,874,539 shares of Greenhill common stock, representing approximately 15.3% of the shares of Greenhill common stock issued and outstanding and entitled to vote at the Special Meeting.

The following table sets forth information regarding ownership of Greenhill common stock by:

We have determined beneficial ownership in accordance with the rules of the SEC, and therefore it represents sole or shared voting or investment power with respect to our securities. Unless otherwise indicated below, to our knowledge, the persons and entities named in the table below have sole voting and sole investment power with respect to all shares that they beneficially own, subject to community property laws where applicable. We have deemed shares of our common stock subject to RSUs and PSUs outstanding as of July 10, 2023, that were exercisable or issuable or will become exercisable or issuable within 60 days of July 10, 2023, to be outstanding and to be beneficially owned by the person holding RSU or PSU for the purpose of computing the percentage ownership of that person, but have not treated them as outstanding for the purpose of computing the percentage ownership of any other person. We have based percentage ownership of our common stock on 18,802,594 shares of our common stock issued and outstanding as of July 10, 2023. Unless otherwise indicated, the address of each named person is c/o Greenhill & Co., Inc., 1271 Avenue of the Americas, New York, New York 10020.

If the Merger is completed, we will have no public stockholders and there will be no public participation in any future meetings of Greenhill stockholders. However, if the Merger is not completed, Greenhill stockholders will continue to be entitled to attend and participate in stockholder meetings.

Greenhill does not anticipate holding a 2024 annual meeting of stockholders if the Merger is completed as currently expected. In the event that the Merger is not completed within the expected time frame, or at all, Greenhill may hold the Greenhill 2024 annual meeting. Any stockholder nominations or proposals for other business intended to be presented at Greenhill’s 2024 annual meeting must be submitted to Greenhill as set forth below:

In order for a stockholder proposal to be considered for inclusion in our proxy statement for the 2024 annual meeting of stockholders, the written proposal must be received at our principal executive offices at 1271 Avenue of the Americas, New York, New York 10020, Attention: General Counsel & Company Secretary, on or before November 14, 2023. The proposal must comply with applicable SEC regulations.

Under our bylaws, director nominations or other business that is not submitted for inclusion in our proxy statement under SEC Rule 14a-8, but is instead sought to be presented directly at the 2024 annual meeting, must be received (A) no earlier than the close of business on January 3, 2024 and no later than the close of business on February 2, 2024 or, (B) in the event that our 2024 annual meeting of stockholders is held prior to April 2, 2024 or after July 11, 2024, notice by the stockholder must be so received no earlier than the 120th day prior to such annual meeting and no later than the close of business on the later of the 90th day prior to such annual meeting or the 10th day following the day on which public announcement of the date of the annual meeting is first made, and, in each case, must comply with the requirements of our bylaws.

For a stockholder’s notice of nomination of one or more director candidates to be included in our proxy materials for our 2024 annual meeting of stockholders, pursuant to the proxy access provision in Section 2.14 of our bylaws, such notice of nomination must be received by our Corporate Secretary at our principal executive offices no earlier than the close of business on October 16, 2023 and no later than the close of business on November 15, 2023, provided that if the 2024 annual meeting is held prior to April 2, 2024 or after June 1, 2024, such notice must be given by the later of the close of business on the date 180 days prior to the meeting date or the 10th day on which public announcement of the date of the annual meeting is first made. The notice must contain the information required by our bylaws, and the stockholder(s) and nominee(s) must comply with the information and other requirements in our bylaws relating to the inclusion of stockholder nominees in our proxy materials. The deadline for providing notice of a solicitation of proxies in support of director nominees other than the registrant’s nominees is March 3, 2024.

The SEC allows us to “incorporate by reference” information into this proxy statement, which means that we can disclose important information to you by referring you to other documents filed separately with the SEC. The information incorporated by reference is deemed to be part of this proxy statement, except for any information superseded by information in this proxy statement or incorporated by reference subsequent to the date of this proxy statement. This proxy statement incorporates by reference the documents set forth below that we have previously filed with the SEC. These documents contain important information about us and our financial condition and are incorporated by reference into this proxy statement.

The following Greenhill filings with the SEC are incorporated by reference:

We also incorporate by reference into this proxy statement additional documents that we may file with the SEC between the date of this proxy statement and the earlier of the date of the Special Meeting or the termination of the Merger Agreement. These documents include periodic reports, such as Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q, as well as Current Reports on Form 8-K and proxy soliciting materials.

Greenhill is subject to the informational requirements of the Exchange Act. We file reports, proxy statements and other information with the SEC. The SEC maintains an Internet site that contains our reports, proxy and information statements and other information at https://sec.gov.

You may obtain any of the documents we file with the SEC, without charge, by requesting them in writing or by telephone from us:

In order for you to receive timely delivery of documents in advance of the Special Meeting, you must make such request by no later than August 9, 2023. Please note that all of our documents that we file with the SEC are also promptly available through our Investor website at https://Greenhill.com/en/investor. The information included on our website is not incorporated by reference into this proxy statement.

If you have any questions concerning the Merger, the Special Meeting or this proxy statement, would like additional copies of this proxy statement or need help voting your shares of Greenhill common stock, please contact our proxy solicitor:

Greenhill has supplied all information relating to Greenhill, and Mizuho Americas has supplied, and Greenhill has not independently verified, all of the information relating to Mizuho Americas and Merger Sub contained in this proxy statement.

You should rely only on the information contained in this proxy statement, the annexes to this proxy statement and the documents that we incorporate by reference in this proxy statement in voting on the Merger. We have not authorized anyone to provide you with information that is different from what is contained in this proxy statement. This proxy statement is dated July 13, 2023. You should not assume that the information contained in this proxy statement is accurate as of any date other than that date (or as of an earlier date if so indicated in this proxy statement), and the mailing of this proxy statement to Greenhill stockholders does not create any implication to the contrary. This proxy statement does not constitute a solicitation of a proxy in any jurisdiction where, or to or from any person to whom, it is unlawful to make a proxy solicitation.