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As filed with the Securities and Exchange Commission on September 13, 2022

No. 333-

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-4

REGISTRATION STATEMENT
UNDER

THE SECURITIES ACT OF 1933

TAILWIND ACQUISITION CORP.

(Exact name of registrant as specified in its charter)

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1545 Courtney Avenue

Los Angeles, CA

Telephone: (646) 432-0610

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Chris Hollod

Chief Executive Officer

1545 Courtney Avenue

Los Angeles, CA 90046

Telephone: (646) 432-0610

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies of all communications, including communications sent to agent for service, should be sent to:

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Approximate date of commencement of proposed sale to the public:

As soon as practicable after this registration statement is declared effective and all other conditions to the Business Combination described in the enclosed proxy statement/prospectus have been satisfied or waived.

If the securities being registered on this Form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box: ☐

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering: ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering: ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

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If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

Exchange Act Rule 13e-4(i) (Cross-Border Issuer Tender Offer) ☐

Exchange Act Rule 14d-l(d) (Cross-Border Third-Party Tender Offer) ☐

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until this registration statement shall become effective on such date as the U.S. Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

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PRELIMINARY PROXY STATEMENT/PROSPECTUS

SUBJECT TO COMPLETION, DATED SEPTEMBER 13, 2022

Tailwind Acquisition Corp.

Dear Stockholder:

On August 5, 2022, Tailwind Acquisition Corp., a Delaware corporation (“Tailwind”), entered into a Business Combination Agreement (as it may be amended, supplemented or otherwise modified from time to time, the “Business Combination Agreement”), by and among Tailwind, Compass Merger Sub, Inc., a Delaware corporation (“Merger Sub”), and Nuburu, Inc., a Delaware corporation (“Nuburu”), a copy of which is attached to this proxy statement/prospectus as Annex A.

The Business Combination Agreement provides for, among other things, the following transactions: (i) Nuburu will change its name to “Nuburu Subsidiary, Inc.”; (ii) the certificate of incorporation of Tailwind will be amended and restated; and (iii) Merger Sub will merge with and into Nuburu, with Nuburu as the surviving company in the Business Combination, and after giving effect to such merger, continuing as a wholly owned subsidiary of New Nuburu (as defined below) (the “Merger”). In addition, in connection with the transactions contemplated by the Business Combination Agreement, Tailwind is expected to change its name to “Nuburu, Inc.” (“New Nuburu”) (such transactions, together with the other transactions contemplated by the Business Combination Agreement, the “Business Combination”).

At the effective time of the Business Combination (the “Effective Time”), in accordance with the terms and subject to the conditions of the Business Combination Agreement, outstanding shares of Nuburu capital stock (other than treasury shares and shares with respect to which appraisal rights under the Delaware General Corporation Law (“DGCL”) are properly exercised and not withdrawn) will be exchanged for shares of common stock, par value $0.0001 per share, of New Nuburu (the “New Nuburu Common Stock”), outstanding options to purchase shares of Nuburu, whether vested or unvested, will be exchanged for comparable options to purchase New Nuburu Common Stock and outstanding restricted stock units of Nuburu will be converted into restricted stock units of New Nuburu, in each case, based on the Common Stock Exchange Ratio (as defined herein) or, with respect to any share of preferred stock of Nuburu for which the Preferred Stock Exchange Ratio (as defined herein) would provide for greater consideration, the applicable Preferred Stock Exchange Ratio with respect to such share. Additionally, immediately prior to the Effective Time, each outstanding convertible promissory note issued by Nuburu (each, a “Company Note”) will be cancelled and converted into shares of Nuburu common stock and, accordingly, at the Effective Time, shall be cancelled and converted into New Nuburu Common Stock in accordance with the foregoing.

Taking these adjustments into account and assuming that the Business Combination were to occur on           , 2023, Tailwind estimates that approximately            shares of New Nuburu Common Stock will be issued to the holders of shares of common stock and preferred stock of Nuburu that are outstanding immediately prior to the Business Combination in exchange for such shares. Additionally, prior to the Effective Time, Tailwind’s Board of Directors intends to declare an issuance in the form of shares of Series A preferred stock (the “Preferred Stock Issuance”), par value $0.0001 per share (“New Nuburu Series A Preferred Stock”), to the holders of record of New Nuburu Common Stock as of the close of business on the closing date of the Business Combination (the “Closing Date”) (other than (a) stockholders of Nuburu who have waived such stockholders’ entire right, title and interest in, to or under, any participation in the Preferred Stock Issuance (which, for clarity, shall exclude such waiver with respect to shares of New Nuburu Common Stock to be received as a result of the conversion of any Company Note) and (b) Tailwind Sponsor LLC, a Delaware limited liability company (the “Sponsor”), who shall have waived right, title and interest in, to or under, a portion of the Preferred Stock Issuance, as further described in the Sponsor Support and Forfeiture Agreement, dated August 5, 2022, by and between the Sponsor and Tailwind (the “Sponsor Support and Forfeiture Agreement”)), with one share of New Nuburu Series A Preferred Stock to be issued in respect of each such share of New Nuburu Common Stock. For clarity, any stockholder of Tailwind that has elected to redeem their Tailwind Shares (as defined herein) in connection with the Business Combination shall not participate in the Preferred Stock Issuance with respect to the shares it has so redeemed, as such holder will not be a record holder of New Nuburu Common Stock with respect to such shares as of the close of business on the Closing Date.

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This proxy statement/prospectus covers             shares of New Nuburu Common Stock (including shares issuable upon exercise of vested options to purchase shares of Nuburu and shares issuable upon the settlement of restricted stock units). The number of shares of New Nuburu Common Stock that this proxy statement/prospectus covers represents the estimated maximum number of shares of New Nuburu Common Stock that may be issued to holders of shares, vested options and restricted stock units of Nuburu in connection with the Business Combination (as more fully described in this proxy statement/prospectus).

Concurrently with the execution of the Business Combination Agreement, Tailwind entered into a Purchase Agreement (the “Lincoln Park Purchase Agreement”) with Lincoln Park Capital Fund, LLC (“Lincoln Park”) to establish a committed funding agreement. Pursuant to the terms of the Lincoln Park Purchase Agreement, following consummation of the Business Combination and upon satisfaction of the conditions set forth in the Lincoln Park Purchase Agreement, including the effectiveness of a registration statement covering the resale of any shares of New Nuburu Common Stock issued to Lincoln Park under the Lincoln Park Purchase Agreement, New Nuburu has the right, but not the obligation, to direct Lincoln Park to purchase certain amounts of New Nuburu Common Stock up to an aggregate of $100 million over the term of the Lincoln Park Purchase Agreement.

Subject to the assumptions set forth under “Basis of Presentation and Glossary” in this accompanying proxy statement/prospectus, the total number of shares of New Nuburu Common Stock expected to be issued in the Business Combination would be approximately 31,239,578 and shareholders of Nuburu who are shareholders immediately prior to the closing of the Business Combination (the “Closing”) would hold, in the aggregate, approximately 86.4% of the issued and outstanding shares of New Nuburu Common Stock immediately following the Closing, assuming no shares of Class A common stock, par value $0.0001 per share, of Tailwind (“Class A Common Stock”) are redeemed.

Tailwind’s units, Class A Common Stock and public warrants are publicly traded on the NYSE under the symbols “TWND.U,” “TWND” and “TWND WS,” respectively. Following the Closing, New Nuburu (formerly Tailwind) will continue to have its New Nuburu Common Stock and public warrants traded under the symbols “BURU” and “BURU WS” respectively. Tailwind warrant holders and those stockholders who do not elect to have their shares redeemed need not deliver their shares of Class A Common Stock or warrant certificates to Tailwind or Tailwind’s transfer agent and such shares and warrants will remain outstanding.

Tailwind will hold a special meeting of stockholders (the “Tailwind Special Meeting”) to consider matters relating to the proposed Business Combination. Tailwind and Nuburu cannot complete the Business Combination unless Tailwind’s stockholders consent to the approval of the Business Combination Agreement and the transactions contemplated thereby, including the issuance of New Nuburu Common Stock to be issued as the Business Combination consideration. Tailwind is sending you this proxy statement/prospectus to ask you to vote in favor of these and the other matters described in this proxy statement/prospectus.

The Tailwind Special Meeting will be held on           , 2023, at            Eastern Time, via a virtual meeting. You may attend the meeting and vote your shares electronically during the meeting via live audio webcast by visiting           . You will need the control number that is printed on your proxy card to enter the Tailwind Special Meeting. Tailwind recommends that you log in at least 15 minutes before the meeting to ensure you are logged in when the Tailwind Special Meeting starts. Please note that you will not be able to attend the Tailwind Special Meeting in person.

YOUR VOTE IS VERY IMPORTANT, REGARDLESS OF THE NUMBER OF SHARES OF CLASS A COMMON STOCK YOU OWN. To ensure your representation at the Tailwind Special Meeting, please complete and return the enclosed proxy card or submit your proxy by following the instructions contained in this proxy statement/prospectus and on your proxy card. Please submit your proxy promptly whether or not you expect to attend the meeting. Submitting a proxy now will NOT prevent you from being able to vote online at the meeting. If you hold your shares in “street name,” you should instruct your broker, bank or other nominee how to vote in accordance with the voting instruction form you receive from your broker, bank or other nominee.

The Tailwind board of directors has unanimously approved the Business Combination Agreement and the transactions contemplated thereby and recommends that Tailwind stockholders vote “FOR” each of the proposals to be considered at the Tailwind Special Meeting.

This proxy statement/prospectus provides you with detailed information about the proposed Business Combination. It also contains or references information about Tailwind and Nuburu and certain related matters. You are encouraged to read this proxy statement/prospectus carefully. In particular, you should read the “Risk Factors” section beginning on page     for a discussion of the risks you should consider in evaluating the proposed Business Combination and how it will affect you.

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If you have any questions regarding the accompanying proxy statement/prospectus, you may contact           , Tailwind’s proxy solicitor, toll-free at            (banks and brokers call        ) or email            at           .

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Neither the Securities and Exchange Commission (the “SEC”) nor any state securities commission has approved or disapproved of the Business Combination, the issuance of New Nuburu Common Stock in connection with the Business Combination or the other transactions described in this proxy statement/prospectus, or passed upon the adequacy or accuracy of the disclosure in this proxy statement/prospectus. Any representation to the contrary is a criminal offense.

This proxy statement/prospectus is dated           , 2023, and is first being mailed to stockholders of Tailwind on or about           , 2023.

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Tailwind Acquisition Corp.

NOTICE OF THE SPECIAL MEETING OF STOCKHOLDERS TO BE HELD ON           , 2023. NOTICE IS HEREBY GIVEN that a special meeting of the stockholders (the “Tailwind Special Meeting”) of Tailwind Acquisition Corp., a Delaware corporation (“Tailwind”), will be held virtually, conducted via live audio webcast at           , Eastern Time, on           , 2023. You will need the control number that is printed on your proxy card to enter the Tailwind Special Meeting. Tailwind recommends that you log in at least 15 minutes before the Tailwind Special Meeting to ensure you are logged in when the meeting starts. Please note that you will not be able to attend the Tailwind Special Meeting in person. You are cordially invited to attend the Tailwind Special Meeting for the following purposes:

We refer to these proposals collectively as the “Advisory Charter Proposals”;

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Only holders of record of shares of Class A Common Stock and Class B Common Stock (together, the “Tailwind Shares”) at the close of business on               , 2023 are entitled to notice of the Tailwind Special Meeting and to vote at the Tailwind Special Meeting and any adjournments or postponements of the Tailwind Special Meeting. A complete list of Tailwind stockholders of record entitled to vote at the Tailwind Special Meeting will be available for ten (10) days before the Tailwind Special Meeting at the principal executive offices of Tailwind for inspection by stockholders during ordinary business hours for any purpose germane to the Tailwind Special Meeting.

The eligible Tailwind stockholder list will also be available at that time on the Tailwind Special Meeting website for examination by any stockholder attending the Tailwind Special Meeting live audio webcast.

Pursuant to the Pre-Closing Tailwind Certificate of Incorporation, Tailwind will provide holders (“public stockholders”) of its Class A Common Stock the opportunity to redeem their shares of Class A Common Stock for cash equal to their pro rata share of the aggregate amount on deposit in the trust account (the “Trust Account”), which holds the proceeds of Tailwind’s initial public offering (the “IPO”) as of two (2) business days prior to the consummation of the transactions contemplated by the Business Combination Proposal (including interest earned on the funds held in the Trust Account and not previously released to Tailwind to pay taxes) upon the Closing. For illustrative purposes, based on funds in the Trust Account of approximately $          million on               , 2023, the estimated per share redemption price would have been approximately $              , excluding additional interest earned on the funds held in the Trust Account and not previously released to Tailwind to pay taxes. Public stockholders may elect to redeem their shares even if they vote for the Business Combination Proposal. In accordance with the Pre-Closing Tailwind Certificate of Incorporation, a public stockholder, together with any of his, her or its affiliates or any other person with whom he, she or it is acting in concert or as a “group” (as defined in Section 13 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)), will be restricted from seeking redemption rights with respect to more than an aggregate of 15% of the Class A Common Stock. Tailwind Sponsor LLC, a Delaware limited liability company (the “Sponsor”), and Tailwind’s officers and directors have agreed to waive their redemption rights in connection with the consummation of the Business Combination with respect to any shares of Class A Common Stock they may hold. Currently, the Sponsor owns approximately 8,355,393 shares of Class B Common Stock. The Sponsor and Tailwind’s directors and officers have agreed to vote any shares of Tailwind common stock owned by them in favor of the Business Combination Proposal. Additionally, Nuburu stockholders representing at least 98% of the outstanding voting power in Nuburu, including certain of Nuburu’s directors and officers have entered into a stockholder support agreement to vote in favor of the Business Combination.

Approval of the Business Combination Proposal, the Director Appointment Proposal, the NYSE Proposal, the Equity Incentive Plan Proposal, the ESPP Proposal and the Adjournment Proposal requires the affirmative vote of a majority of the votes cast by holders of common stock, voting together as a single class at a meeting at which a quorum is present. Approval of the Charter Proposal and each of the Advisory Charter Proposals requires the affirmative vote of a majority of the shares of common stock outstanding, voting together as a single class. Approval of the Charter Proposal and Advisory Charter Proposals 3A and 3B also requires the affirmative vote of a majority of the shares of Class B Common Stock outstanding, voting as a separate class. The Tailwind board of directors has already approved each of the proposals. Given that the Sponsor owns 100% of the outstanding Class B Common Stock (amounting to approximately 72.1% of the outstanding shares of Tailwind common stock), each of the proposals will be approved if the Sponsor votes in favor of such proposal, even if all other shareholders vote against such proposal. The Sponsor has agreed to vote in favor of each of the proposals.

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As of            , 2023, there was approximately $32.4 million (excluding the Extension Loan) in the Trust Account, which Tailwind intends to use for the purposes of consummating a business combination within the time period described in this proxy statement/prospectus. Each redemption of Class A Common Stock by public stockholders will decrease the amount of cash held in the Trust Account that would be available to New Nuburu after the Closing. Tailwind will not consummate the Business Combination if the redemption of Class A Common Stock would result in Tailwind’s failure to have at least $5,000,001 of net tangible assets (as determined in accordance with Rule 3a51-1(g)(1) of the Exchange Act) (or any successor rule).

If Tailwind stockholders fail to approve the Business Combination Proposal, the NYSE Proposal, the Charter Proposal, the Equity Incentive Plan Proposal or the ESPP Proposal, the Business Combination will not occur. This proxy statement/prospectus summarizes the material terms and conditions of the Business Combination Agreement and the transactions contemplated thereby, as well as the proposals to be considered at the Tailwind Special Meeting. Please review the proxy statement/prospectus carefully.

Your vote is very important, regardless of the number of Tailwind Shares you own. Whether or not you plan to attend the Tailwind Special Meeting, please complete, sign, date and mail the enclosed proxy card in the postage-paid envelope provided at your earliest convenience. You may also submit a proxy by telephone or via the Internet by following the instructions printed on your proxy card. If you hold your shares through a broker, bank or other nominee, you should direct the vote of your shares in accordance with the voting instruction form received from your broker, bank or other nominee.

The Tailwind board of directors has unanimously approved the Business Combination Agreement and the transactions contemplated thereby and recommends that you vote “FOR” the Business Combination Proposal, “FOR” the Charter Proposal, “FOR” the Advisory Charter Proposals, “FOR” the Director Appointment Proposal, “FOR” the NYSE Proposal, “FOR” the Equity Incentive Plan Proposal, “FOR” the ESPP Proposal and, if required, “FOR” the Adjournment Proposal.

If you have any questions or need assistance with voting, please contact       , Tailwind’s proxy solicitor, toll-free at                   (banks and brokers call                    ) or email at                   .

If you plan to attend the Tailwind Special Meeting and are a beneficial investor who owns your investments through a bank, broker, or other nominee you will need to contact Continental Stock Transfer & Trust Company (“CST”) to receive a control number. Please read carefully the sections in the proxy statement/prospectus regarding attending and voting at the Tailwind Special Meeting to ensure that you comply with these requirements.

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NEITHER THE U.S. SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES REGULATORY AGENCY HAS APPROVED OR DISAPPROVED THE TRANSACTIONS DESCRIBED IN THIS PROXY STATEMENT/PROSPECTUS OR ANY OF THE SECURITIES TO BE ISSUED IN THE BUSINESS COMBINATION, PASSED UPON THE MERITS OR FAIRNESS OF THE BUSINESS COMBINATION OR RELATED TRANSACTIONS OR PASSED UPON THE ADEQUACY OR ACCURACY OF THE DISCLOSURE IN THIS PROXY STATEMENT/PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY CONSTITUTES A CRIMINAL OFFENSE.

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ADDITIONAL INFORMATION

You may request copies of this proxy statement/prospectus and any other publicly available information concerning Tailwind, without charge, by written request to Tailwind Acquisition Corp., 1545 Courtney Avenue, Los Angeles, CA, or by telephone request at (646) 432-0610; or                            , our proxy solicitor, by calling                            (toll free), or banks and brokers can call                         , or by emailing                                     or from the SEC through the SEC website at http://www.sec.gov.

In order for Tailwind’s stockholders to receive timely delivery of the documents in advance of the Special Meeting of Tailwind to be held on                         , 2023, you must request the information no later than five business days prior to the date of the Special Meeting, by                    , 2023.

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MARKET AND INDUSTRY DATA

In this proxy statement/prospectus, we present industry data, information and statistics regarding the markets in which Nuburu competes as well as publicly available information, industry and general publications and research and studies conducted by third parties. This information is supplemented where necessary with Nuburu’s own internal estimates and information obtained from discussions with its customers, taking into account publicly available information about other industry participants and Nuburu’s management’s judgment where information is not publicly available. This information appears in “Information About Nuburu” and other sections of this proxy statement/prospectus.

Industry publications, research, studies and forecasts generally state that the information they contain has been obtained from sources believed to be reliable. However, forecasts and other forward-looking information obtained from these sources are subject to the same qualifications and uncertainties as the other forward-looking statements in this proxy statement/prospectus. These forecasts and forward-looking information are subject to uncertainty and risk due to a variety of factors, including those described under “Risk Factors.” These and other factors could cause results to differ materially from those expressed in any forecasts or estimates.

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TRADEMARKS

The Nuburu design logo and the Nuburu mark appearing in this proxy statement/prospectus are the property of Nuburu, Inc. Trademarks, trade names and service marks of other companies appearing in this prospectus/proxy statement are the property of their respective holders. We have omitted the ^® and ™ designations, as applicable, for the trademarks used in this prospectus/proxy statement.

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BASIS OF PRESENTATION AND GLOSSARY

As used in this proxy statement/prospectus, unless otherwise noted or the context otherwise requires, references to:

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Unless otherwise specified, the share calculations and ownership percentages set forth in this proxy statement/prospectus with respect to New Nuburu’s stockholders immediately following the Business Combination are for illustrative purposes only and assume the following:

If the actual facts are different than these assumptions, the ownership percentages in New Nuburu will be different. In particular, the number of shares of New Nuburu Common Stock issued to the holders of shares of common stock and preferred stock of Nuburu upon consummation of the Business Combination will fluctuate based on the number of shares underlying vested Nuburu Options (and the exercise price of such options), at the Closing. Vested Nuburu Options and Nuburu RSUs are taken into account for purposes of allocating the implied $             fixed pre-transaction equity value of Nuburu among the holders of shares and equity awards of Nuburu, with the value allocable to such options and restricted stock units being determined based on the treasury stock method.

Beneficial ownership throughout this proxy statement/prospectus with respect to New Nuburu’s stockholders is determined according to the rules of the SEC, which generally provide that a person has beneficial ownership of a security if he, she or it possesses sole or shared voting or investment power over that security, including options and warrants that are currently exercisable or exercisable within 60 days of such disclosure.

Unless specified otherwise, amounts in this proxy statement/prospectus are presented in United States (“U.S.”) dollars.

Defined terms in the financial statements contained in this proxy statement/prospectus have the meanings ascribed to them in the financial statements.

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QUESTIONS AND ANSWERS

The following are answers to certain questions that you, as a stockholder of Tailwind, may have regarding the Business Combination and the stockholder meeting. We urge you to read carefully the remainder of this proxy statement/prospectus because the information in this section may not provide all the information that might be important to you in determining how to vote. Additional important information is also contained in the annexes to this proxy statement/prospectus.

QUESTIONS AND ANSWERS ABOUT THE BUSINESS COMBINATION

Tailwind will hold the Tailwind Special Meeting to consider matters relating to the proposed Business Combination. See “The Business Combination Agreement.” In addition, a copy of the Business Combination Agreement is attached to this proxy statement/prospectus as Annex A. We urge you to carefully read this proxy statement/prospectus and the Business Combination Agreement in their entirety. Tailwind and Nuburu cannot complete the Business Combination unless Tailwind’s stockholders approve the Business Combination Agreement and the transactions contemplated thereby. Tailwind is sending you this proxy statement/prospectus to ask you to vote in favor of these and the other matters described in this proxy statement/prospectus.

The Business Combination cannot be completed unless Tailwind’s stockholders approve the Business Combination Proposal, the Charter Proposal, the NYSE Proposal, the Equity Incentive Plan Proposal and the ESPP Proposal, each as set forth in this proxy statement/prospectus. Information about the Tailwind Special Meeting, the Business Combination and the other business to be considered by stockholders at the Tailwind Special Meeting is contained in this proxy statement/prospectus.

This document constitutes a proxy statement of Tailwind and a prospectus of Tailwind. It is a proxy statement because the board of directors of Tailwind is soliciting proxies using this proxy statement/prospectus from its stockholders. It is a prospectus because Tailwind, in connection with the Business Combination, is offering (i) shares of New Nuburu Common Stock in exchange for the outstanding shares of Nuburu common stock and preferred stock and (ii) shares of New Nuburu Series A Preferred Stock to holders of record of New Nuburu Common Stock as of the close of business on the Closing Date (other than (a) stockholders of Nuburu who have waived such stockholders’ entire right, title and interest in, to or under, any participation in the Preferred Stock Issuance (which, for clarity, shall exclude such waiver with respect to shares of New Nuburu Common Stock to be received as a result of the conversion of any Company Note) and (b) the Sponsor, who shall have waived right, title and interest in, to or under, a portion of the Preferred Stock Issuance, as further described in Sponsor Support and Forfeiture Agreement). See “The Business Combination Agreement — Merger Consideration.”

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deliver their shares of Class A Common Stock or warrant certificates to Tailwind or Tailwind’s transfer agent and such shares and warrants will remain outstanding.

Each share of Nuburu common stock, par value $0.0001 per share (“Nuburu Common Stock”) issued and outstanding shall be canceled and converted into the right to receive the number of shares of New Nuburu Common Stock equal to the Common Stock Exchange Ratio.

Each outstanding option to purchase shares of Nuburu Common Stock (each such option, a “Nuburu Option”), whether vested or unvested, will be converted into an option to purchase a number of shares of New Nuburu Common Stock (such option, an “Exchanged Option”) equal to the product (rounded down to the nearest whole number) of (x) the number of shares of Nuburu Common Stock subject to such Nuburu Option immediately prior to the Effective Time and (y) the Common Stock Exchange Ratio, at an exercise price per share (rounded up to the nearest whole cent) equal to the quotient of (A) the exercise price per share of such Nuburu Option immediately prior to the Effective Time divided by (B) the Common Stock Exchange Ratio. Except as specifically provided above, following the Effective Time, each Exchanged Option will continue to be governed by the same terms and conditions, including vesting and exercisability terms, as were applicable to the corresponding former Nuburu Option immediately prior to the Effective Time.

Each outstanding restricted stock unit granted by Nuburu (each a “Nuburu RSU”) will be converted into a restricted stock unit of New Nuburu Common Stock (such restricted stock unit covering New Nuburu Common Stock, an “Exchanged RSU”) equal to the product (rounded down to the nearest whole number) of (x) the number of shares subject to a Nuburu RSU immediately prior to the Effective Time and (y) the Common Stock Exchange Ratio. Except as specifically provided above, following the Effective Time, each Exchanged RSU will continue to be governed by the same terms and conditions as were applicable to the corresponding former Nuburu RSU immediately prior to the Effective Time.

Each outstanding warrant to purchase shares of Nuburu Common Stock will be treated in accordance with its terms, as may be amended prior to the Closing, with any amendments subject to Tailwind’s prior written consent, not to be unreasonably withheld, conditioned, or delayed.

Each Company Note will be canceled and converted into (A) shares of Nuburu Common Stock in accordance with the terms of such Company Note as of immediately prior to the Effective Time, which shares shall then be outstanding as of immediately prior to the Effective Time and subsequently converted into New Nuburu Common Stock (and with such shares being entitled to participate in the Preferred Stock Issuance).

The “Common Stock Exchange Ratio” means the quotient obtained by dividing (x) the Aggregate Common Stock Merger Consideration by (y) the number of Fully-Diluted Company Shares. The “Aggregate Common Stock Merger Consideration” means a number of shares of New Nuburu Common Stock equal to (a) 35,000,000 less (b) the aggregate number of New Nuburu Common Stock issuable in respect of Unconverted Preferred Stock pursuant to Section 3.01(a)(i) of the Business Combination Agreement. “Fully-Diluted Company Shares” means an amount equal to, without duplication, (i) the aggregate number of shares of Nuburu capital stock that are issued and outstanding as of immediately prior to the Effective Time on a fully-diluted, as converted-to Company Common Stock basis, plus (ii) the aggregate number of shares of Nuburu Common Stock issuable upon the full exercise, exchange or conversion of Nuburu warrants, Nuburu Options, Nuburu RSUs and

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Company Notes that are outstanding as of immediately prior to the Effective Time; provided, however, that “Fully-Diluted Shares” shall exclude (A) all Unconverted Preferred Stock and (B) certain equity set forth in the schedules to the Business Combination Agreement.

The “Preferred Stock Exchange Ratio” means, with respect to each share of Nuburu Preferred Stock, the number of shares of New Nuburu Common Stock which a share of such series of Preferred Stock is to be cancelled and converted into the right to receive pursuant to the applicable provisions of the Business Combination Agreement. The Business Combination Agreement provides that each share of Nuburu Preferred Stock issued and outstanding immediately prior to the Effective Time shall be cancelled and converted into the right to receive the number of shares of New Nuburu Common Stock equal to the greater of (A) the quotient obtained from (x) the applicable Preferred Stock Liquidation Preference of such share of Nuburu Preferred Stock divided by (y) $10.00, and (B) the product of (x) the number of shares of New Nuburu Common Stock that such share of Company Preferred Stock would be entitled to convert into as of immediately prior to the Effective Time in accordance with the Pre-Closing Nuburu Certificate of Incorporation, multiplied by (y) the Common Stock Exchange Ratio.

“Preferred Stock Liquidation Preference” means

As of the date of this proxy statement/prospectus, we currently estimate that the Common Stock Exchange Ratio and the Preferred Stock Exchange Ratios will be approximately as follows.

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The foregoing assumes that no additional Company Notes will be issued other than the $5.3 million that have been issued by Nuburu as of the date of this prospectus/proxy statement, and assumes accrual of interest on the Company Notes through August 31, 2022. The foregoing represents management’s estimates based on information available as of the date of this prospectus/proxy statement and is subject to change.

In multiple closings over the course of March and August 2022, Nuburu issued and sold Company Notes with aggregate gross proceeds of $5.3 million. Nuburu may sell additional Company Notes prior to Closing. Pursuant to their terms, the Company Notes accrue interest at a rate of 8% per annum. Unless earlier repaid or converted pursuant to their terms, the outstanding principal amount of and all accrued and unpaid interest on the Company Notes (the “Conversion Amount”) shall, immediately prior to the consummation of the Business Combination, automatically convert into that number of shares of Nuburu Common Stock that would, upon consummation of the Business Combination, receive a number of New Nuburu Common Stock equal to (x) the Conversion Amount divided by (y) $8.50. Each share of New Nuburu Common Stock converted in this manner is included in the Aggregate Common Stock Merger Consideration being issued to Nuburu equityholders.

In addition, each share of New Nuburu Common Stock issued in respect of Company Notes shall be entitled to participate in the Preferred Stock Issuance. As such, assuming that Nuburu does not issue any additional Company Notes in excess of the $5.3 million that have been issued as of the date of this proxy statement/prospectus and that the Closing occurs on August 31, 2022 an amount of 625,772 shares of Series A Preferred Stock in the aggregate (such amount being the sum of $5.3 million principal amount of and the accrued and unpaid interest on the Company Notes, divided by $8.50) would be issued to the holders of the Company Notes. If any additional Company Notes are issued after the date of this proxy statement/prospectus, or if the Closing occurs after    , 2023 so that additional interest accrues on the Company Notes, then additional shares of New Nuburu Common Stock would be issued to the holders of the Company Notes and, by virtue of the Preferred Stock Issuance, an equal additional amount of shares of Series A Preferred Stock would be issued to the holders of the Company Notes.

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Moreover, the process of government review, whether by the CFIUS or otherwise, could be lengthy and we have limited time to complete the Business Combination. If we cannot complete the Business Combination by March 9, 2023 because the transaction is still under review or because the Business Combination is ultimately prohibited by CFIUS or another U.S. government entity, we may be required to liquidate. If we liquidate, our public stockholders may only receive $     per share of Class A Common Stock, plus any interest that accrues on the amount on deposit in the Trust Account prior to the liquidation date and our Public Warrants and Private Placement Warrants will expire worthless. This will also cause you to lose the investment opportunity in Nuburu and the chance of realizing future gains on your investment through any price appreciation in the combined company.

QUESTIONS AND ANSWERS ABOUT THE TAILWIND SPECIAL MEETING

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The Business Combination will not occur unless Tailwind stockholders approve each of the proposals specified in this proxy statement/prospectus, other than the Director Appointment Proposals, the Advisory Charter Proposals and the Adjournment Proposal. Given that the Sponsor owns 100% of the outstanding Class B Common Stock (amounting to approximately 72.1% of the outstanding shares of Tailwind common stock), each of the proposals will be approved if the Sponsor votes in favor of such proposal, even if all other shareholders vote against such proposal. The Sponsor has agreed to vote in favor of each of the proposals. See “Other Agreements — Tailwind Sponsor Support Agreement” for more information.

On September 9, 2020, Tailwind completed its IPO, generating gross proceeds of $334,215,700, which were placed in the Trust Account. Following the Extension Redemptions (as defined below), a total of approximately $32.4 million (excluding the Extension Loan) remains in the Trust Account as of September 12, 2022. Since Tailwind’s IPO, Tailwind’s activity has been limited to the evaluation of business combination candidates and efforts to consummate the Business Combination Agreement, dated March 1, 2021, by and among Tailwind, Merger Sub, QOMPLX, Inc., a Delaware corporation, and Rationem, LLC, a Delaware limited liability company, which was terminated on August 17, 2021.

Based on its due diligence investigations of Nuburu and the industry in which it operates, including the financial and other information provided by Nuburu in the course of their negotiations in connection with the Business Combination Agreement, Tailwind believes that Nuburu aligns well with the objectives laid out in its investment thesis. As a result, Tailwind believes that a business combination with Nuburu will provide Tailwind stockholders with an opportunity to participate in the ownership of a publicly-listed company with significant growth potential at an attractive valuation. See “The Business Combination — The Tailwind Board of Directors’ Reasons for the Business Combination.”

Notwithstanding the foregoing, a holder of Class A Common Stock, together with any affiliate of such holder or any other person with whom such holder is acting in concert or as a “group” (as defined in Section 13(d)(3) of the Exchange Act), will

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be restricted from seeking redemption with respect to more than 15% of the Class A Common Stock. Accordingly, no shares of Class A Common Stock in excess of 15% held by a public stockholder, together with any affiliate of such holder or any other person with whom such holder is acting in concert or as a “group,” will be redeemed.

Holders of the outstanding public warrants of Tailwind do not have redemption rights with respect to such warrants in connection with the transactions contemplated by the Business Combination Proposal. For clarity, any stockholder of Tailwind that has elected to redeem its shares in connection with the Business Combination shall not participate in the Preferred Stock Issuance with respect to the shares it has so redeemed, as such holder will not be a record holder of New Nuburu Common Stock with respect to such shares as of the close of business on the Closing Date.

Under the Pre-Closing Tailwind Certificate of Incorporation, the Business Combination may be consummated only if Tailwind has at least $5,000,001 of net tangible assets after giving effect to all holders of Class A Common Stock that properly demand redemption of their shares for cash.

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proceeds held in the Trust Account could be subject to claims that could take priority over those of Tailwind’s public stockholders exercising redemption rights, regardless of whether such holders vote for or against the Business Combination Proposal. Therefore, the per share distribution from the Trust Account in such a situation may be less than originally anticipated due to such claims. Your vote on any proposal other than the Business Combination Proposal will have no impact on the amount you will receive upon exercise of your redemption rights.

Any request for redemption, once made by a holder of Class A Common Stock, may be withdrawn at any time up to the time the vote is taken with respect to the Business Combination Proposal at the Tailwind Special Meeting, and may be permitted to be withdrawn following the vote at the discretion of the Tailwind board of directors. If you deliver your shares for redemption to Tailwind’s transfer agent and later decide prior to the Tailwind Special Meeting not to elect redemption, you may request that Tailwind’s transfer agent return the shares (physically or electronically).

Any corrected or changed proxy card or written demand of redemption rights must be received by Tailwind’s transfer agent prior to the vote taken on the Business Combination Proposal at the Tailwind Special Meeting. No demand for redemption will be honored unless the holder’s stock has been delivered (either physically or electronically) to the transfer agent prior to the vote at the Tailwind Special Meeting.

If a holder of Class A Common Stock properly makes a request for redemption and the shares of Class A Common Stock are delivered as described to Tailwind’s transfer agent as described herein, then, if the Business Combination is consummated, Tailwind will redeem these shares for a pro rata portion of funds deposited in the Trust Account. If you exercise your redemption rights, then you will be exchanging your shares of Class A Common Stock for cash. Any stockholder of Tailwind that has elected to redeem its shares in connection with the Business Combination shall not participate in the Preferred Stock Issuance with respect to the shares it has so redeemed, as such holder will not be a record holder of New Nuburu Common Stock with respect to such shares as of the close of business on the Closing Date.

For a discussion of the material U.S. federal income tax considerations for holders of Class A Common Stock with respect to the exercise of these redemption rights, see “Material U.S. Federal Income Tax Consequences — U.S. Federal Income Tax Consequences of a Redemption of Tailwind Public Shares.”

With regard to the SEC’s investment company proposals included in the SPAC Rule Proposals, the funds in the Trust Account were, since the IPO and until September 6, 2022, held only in U.S. government treasury bills with a maturity of 185 days or less or in money market funds investing solely in U.S. Treasuries, to mitigate the risk of being viewed as operating an unregistered investment company (including pursuant to the subjective test of Section 3(a)(1)(A) of the Investment Company Act). On September 2, 2022, Tailwind instructed CST, the trustee managing the Trust Account, to hold

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all funds in the Trust Account in cash until the earlier of consummation of the Business Combination and liquidation of Tailwind.

As of the Tailwind record date, 5,794,118 Tailwind Shares would be required to achieve a quorum.

The Charter Proposal: Approval of the Charter Proposal requires the affirmative vote of a majority of the Tailwind common stock outstanding, voting together as a single class and the affirmative vote by the holders of a majority of the shares of

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Class B Common Stock outstanding, voting as a separate class. The Business Combination is conditioned upon the approval of the Charter Proposal, subject to the terms of the Business Combination Agreement. Notwithstanding the approval of the Charter Proposal, if the Business Combination is not consummated for any reason, the actions contemplated by the Charter Proposal will not be effected.

The Advisory Charter Proposals: Approval of the Advisory Charter Proposals requires the affirmative vote of a majority of the Tailwind common stock outstanding, voting together as a single class, and, for Advisory Charter Proposals 3A and 3B, the affirmative vote by the holders of a majority of the shares of Class B Common Stock outstanding, voting as a separate class. The approval of the Advisory Charter Proposals are non-binding and advisory in nature and the Business Combination does NOT depend on their approval. Notwithstanding the approval of the Advisory Charter Proposals, if the Business Combination is not consummated for any reason, the actions contemplated by the Advisory Charter Proposals will not be effected.

The Director Appointment Proposal: The affirmative vote of a majority of the votes cast by holders of Tailwind common stock, voting together as a single class at a meeting at which a quorum is present, is required to approve the Director Appointment Proposal. The Business Combination is not conditioned upon the approval of the Director Appointment Proposal. Notwithstanding the approval of the Director Appointment Proposal, if the Business Combination is not consummated for any reason, the actions contemplated by the Director Appointment Proposal will not be effected.

The NYSE Proposal: The affirmative vote of a majority of the votes cast by holders of Tailwind common stock, voting together as a single class at a meeting at which a quorum is present, is required to approve the NYSE Proposal. The Business Combination is conditioned upon the approval of the NYSE Proposal, subject to the terms of the Business Combination Agreement. Notwithstanding the approval of the NYSE Proposal, if the Business Combination is not consummated for any reason, the actions contemplated by the NYSE Proposal will not be effected.

The Equity Incentive Plan Proposal: The affirmative vote of a majority of the votes cast by holders of Tailwind Common Stock, voting together as a single class at a meeting at which a quorum is present, is required to approve the Equity Incentive Plan Proposal. The Business Combination is conditioned upon the approval of the Equity Incentive Plan Proposal, subject to the terms of the Business Combination Agreement. Notwithstanding the approval of the Equity Incentive Plan Proposal, if the Business Combination is not consummated for any reason, the actions contemplated by the Equity Incentive Plan Proposal will not be effected.

The ESPP Proposal: The affirmative vote of a majority of the votes cast by holders of Tailwind Common Stock, voting together as a single class at a meeting at which a quorum is present, is required to approve the ESPP Proposal. The Business Combination is conditioned upon the approval of the ESPP Proposal, subject to the terms of the Business Combination Agreement. Notwithstanding the approval of the ESPP Proposal, if the Business Combination is not consummated for any reason, the actions contemplated by the ESPP Proposal will not be effected

The Adjournment Proposal: The affirmative vote of a majority of the votes cast by holders of Tailwind Common Stock, voting together as a single class at a meeting at which a quorum is present, is required to approve the Adjournment Proposal. The Business Combination is not conditioned upon the approval of the Adjournment Proposal.

Given that the Sponsor owns 100% of the outstanding Class B Common Stock (amounting to approximately 72.1% of the outstanding shares of Tailwind common stock), each of the proposals will be approved if the Sponsor votes in favor of such proposal, even if all other shareholders vote against such proposal. The Sponsor has agreed to vote in favor of each of the proposals. See “Other Agreements — Tailwind Sponsor Support Agreement” for more information.

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experience a negative rate of return in New Nuburu. Accordingly, the Sponsor may benefit from the completion of the Business Combination, even in a scenario where other Tailwind stockholders may not similarly benefit. The Sponsor is thereby incentivized to complete an acquisition, even if it might be of a less-favorable target company or on terms less favorable to Tailwind’s stockholders, rather than liquidate. The Tailwind board of directors was aware of and considered these interests to the extent such interests existed at the time, among other matters, in approving the Business Combination Agreement and in recommending that the Business Combination Agreement and the transactions contemplated thereby be approved by the stockholders of Tailwind. See “The Business Combination — Interests of Tailwind’s Directors and Officers in the Business Combination” and “Risk Factors — Risks Related to the Business Combination — Since the Sponsor and Tailwind’s officers and directors who are members of the Sponsor have interests that are different, or in addition to (and which may conflict with), the interests of the public stockholders, a conflict of interest may have existed in determining whether the Business Combination with Nuburu is appropriate as a business combination. Such interests include that Sponsor will lose its entire investment in us if our business combination is not completed.”

Stockholders who choose to participate in the Tailwind Special Meeting can vote their shares electronically during the meeting via live audio webcast by visiting www.                . You will need the control number that is printed on your proxy card to enter the Tailwind Special Meeting. Tailwind recommends that you log in at least 15 minutes before the meeting to ensure you are logged in when the Tailwind Special Meeting starts.

If your shares are held in “street name” through a broker, bank or other nominee, your broker, bank or other nominee will send you separate instructions describing the procedure for voting your shares. “Street name” stockholders who wish to vote at the Tailwind Special Meeting will need to obtain a proxy form from their broker, bank or other nominee.

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You can pre-register to attend the virtual Tailwind Special Meeting three days prior to the meeting date starting             , 2023 at            Eastern Time. Enter the URL address into your browser             , enter your control number, name and email address. Once you pre-register you can vote or enter questions in the chat box. At the start of the meeting you will need to re-log in using your control number and will also be prompted to enter your control number if you vote during the meeting. Tailwind recommends that you log in at least 15 minutes before the meeting to ensure you are logged in when the special meeting starts.

Beneficial investors, who own their investments through a bank or broker, will need to contact CST to receive a control number. If you plan to vote at the Tailwind Special Meeting you will need to have a legal proxy from your bank, broker, or other nominee or if you would like to join and not vote CST will issue you a guest control number with proof of ownership. Either way you must contact CST for specific instructions on how to receive the control number. We can be contacted at the number or email address above. Please allow up to 72 hours prior to the meeting for processing your control number.

If you do not have internet capabilities, you can listen to the meeting by dialing +1                (toll- free) outside the U.S. and Canada +1             (standard rates apply) when prompted enter the pin number         #. This is a listen-only option and you will not be able to vote or enter questions during the meeting.

Under the rules of the NYSE, brokers who hold shares in “street name” for a beneficial owner of those shares typically have the authority to vote in their discretion on “routine” proposals when they have not received instructions from beneficial owners. However, brokers are not permitted to exercise their voting discretion with respect to the approval of matters that the NYSE determines to be “non-routine” without specific instructions from the beneficial owner. It is expected that all proposals to be voted on at the Tailwind Special Meeting are “non-routine” matters.

If you are a holder of Tailwind Shares holding your shares in “street name” and you do not instruct your broker, bank or other nominee on how to vote your shares, your broker, bank or other nominee will not vote your shares on any of the proposals presented in this proxy statement/prospectus. The failure of your broker to vote will have no effect on the vote count for such proposals.

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Special Meeting. However, you will not be able to seek redemption of your shares of Class A Common Stock because you will no longer be able to deliver them for cancellation upon the consummation of the Business Combination in accordance with the provisions described herein. If you transfer your shares of Class A Common Stock prior to the Tailwind record date, you will have no right to vote those shares at the Tailwind Special Meeting or redeem those shares for a pro rata portion of the proceeds held in the Trust Account.

If you are a holder of Tailwind Shares that attends the Tailwind Special Meeting virtually and fails to vote, or if you vote abstain, your failure to vote or abstention will have no effect on the vote count for the Business Combination Proposal, the Director Appointment Proposal, the NYSE Proposal, the Equity Incentive Plan Proposal, the ESPP Proposal or the Adjournment Proposal and, for holders of Class A common stock, your failure to vote or abstention will have no effect on the vote count for the Charter Proposal and the Advisory Charter Proposals. However, for holders of Class B Common Stock only, your failure to vote or abstention will have the same effect as a vote “AGAINST” the Charter Proposal and Advisory Charter Proposals 3A and 3B.

If you are a stockholder of record of Tailwind and you choose to send a written notice or to mail a new proxy, you must submit your notice of revocation or your new proxy to Tailwind Acquisition Corp., 1545 Courtney Avenue, Los Angeles, CA 90046 and it must be received at any time before the vote is taken at the Tailwind Special Meeting. Any proxy that you submitted may also be revoked by submitting a new proxy by mail, or online or by telephone, not later than 11:59 p.m. Eastern Time on          , 2023, or by voting online at the Tailwind Special Meeting. Simply attending the Tailwind Special Meeting will not revoke your proxy. If you have instructed a broker, bank or other nominee to vote your Tailwind Shares, you must follow the directions you receive from your broker, bank or other nominee in order to change or revoke your vote.

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SUMMARY

This summary highlights selected information included in this proxy statement/prospectus and does not contain all of the information that may be important to you. You should read this entire document and its annexes and the other documents to which we refer before you decide how to vote.

The Merger and the Business Combination Agreement

The terms and conditions of the Business Combination are contained in the Business Combination Agreement, which is attached as Annex A to this proxy statement/prospectus. We encourage you to read the Business Combination Agreement carefully, as it is the legal document that governs the Business Combination.

If the Business Combination Agreement is approved and adopted and the Business Combination is subsequently completed, Merger Sub will merge with and into Nuburu, with Nuburu surviving the Business Combination as a wholly owned subsidiary of Tailwind.

Merger Consideration

In accordance with the terms and subject to the conditions of the Business Combination Agreement, outstanding shares of Nuburu will be converted into the right to receive New Nuburu Common Stock, outstanding restricted stock units granted by Nuburu will be converted into restricted stock units of New Nuburu Common Stock, outstanding options to purchase shares of Nuburu stock will be converted into options to purchase shares of New Nuburu Common Stock and outstanding convertible promissory notes issued by Nuburu will be converted into shares of Nuburu Common Stock and, following such conversion, converted into shares of New Nuburu Common Stock (and with such shares with respect to the convertible promissory notes being entitled to participate in the Preferred Stock Issuance).

Recommendation of the Tailwind Board of Directors

The Tailwind board of directors has unanimously determined that the Business Combination, on the terms and conditions set forth in the Business Combination Agreement, is advisable and in the best interests of Tailwind and its stockholders and has directed that the proposals set forth in this proxy statement/prospectus be submitted to its stockholders for approval at the Tailwind Special Meeting on the date and at the time and place set forth in this proxy statement/prospectus. The Tailwind board of directors unanimously recommends that Tailwind’s stockholders vote “FOR” the Business Combination Proposal, FOR” the Charter Proposal, “FOR” the Advisory Charter Proposals, “FOR” the Director Appointment Proposal, “FOR” the NYSE Proposal, “FOR” the Equity Incentive Plan Proposal, “FOR” the ESPP Proposal and “FOR” the Adjournment Proposal (if necessary). See “The Business Combination — The Tailwind Board of Directors’ Reasons for the Business Combination.”

Tailwind Special Meeting of Stockholders

The Tailwind Special Meeting will be held on                , 2023, at                Eastern Time, via a virtual meeting. At the Tailwind Special Meeting, Tailwind stockholders will be asked to approve the Business Combination Proposal, the Charter Proposal, the Advisory Charter Proposals, the Director Appointment Proposal, the NYSE Proposal, the Equity Incentive Plan Proposal, the ESPP Proposal and, if necessary, the Adjournment Proposal.

The Tailwind board of directors has fixed the close of business on                , 2023 (“Tailwind record date”) as the record date for determining the holders of Tailwind common stock entitled to receive notice of and to vote at the Tailwind Special Meeting. As of the Tailwind record date, there were 3,232,841 shares of Class A Common Stock and 8,355,393 shares of Class B Common Stock outstanding and entitled to vote at the Tailwind Special Meeting held by holders of record. Each share of Tailwind common stock entitles the holder to one (1) vote at the Tailwind Special Meeting on each proposal to be considered at the Tailwind Special Meeting. As of the Tailwind record date, the Sponsor and Tailwind’s directors and executive officers and their affiliates owned and were entitled to vote 8,355,393 Tailwind Shares, representing approximately 72.1% of the Tailwind Shares outstanding on that date. Tailwind currently expects that the Sponsor and its directors and officers will vote their shares in favor of the proposals set forth in this proxy statement/prospectus pursuant to an agreement entered into in connection with the Business Combination Agreement. As of the Tailwind record date, Nuburu did not beneficially hold any Tailwind Shares.

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A majority of the voting power of the issued and outstanding Tailwind common stock entitled to vote at the Tailwind Special Meeting must be present, online or represented by proxy, at the Tailwind Special Meeting to constitute a quorum and in order to conduct business at the Tailwind Special Meeting.

Approval of the Business Combination Proposal, the Director Appointment Proposal, the NYSE Proposal, the Equity Incentive Plan Proposal, the ESPP Proposal and the Adjournment Proposal require the affirmative vote of a majority of the votes cast by holders of Tailwind common stock, voting together as a single class at a meeting at which a quorum is present. Approval of the Charter Proposal and each of the Advisory Charter Proposals requires the vote of a majority of the Tailwind common stock outstanding, voting together as a single class at a meeting at which a quorum is present. Approval of the Charter Proposal and Adviosry Charter Proposals 3A and 3B also requires the affirmative vote of a majority of Class B Common Stock outstanding, voting as a separate class. The Tailwind board of directors has already approved each of the proposals (excluding the Adjournment Proposal which will only be introduced as needed if any of the other Proposals fail to achieve the required votes). Given that the Sponsor owns 100% of the outstanding Class B Common Stock (amounting to approximately 72.1% of the outstanding shares of Tailwind common stock), each of the proposals will be approved if the Sponsor votes in favor of such proposal, even if all other shareholders vote against such proposal. The Sponsor has agreed to vote in favor of each of the proposals. See “Other Agreements — Tailwind Sponsor Support Agreement” for more information.

If Tailwind stockholders fail to approve the Business Combination Proposal, the Charter Proposal, the NYSE Proposal, the Equity Incentive Plan Proposal or the ESPP Proposal, the Business Combination will not occur. The Adjournment Proposal is not conditioned on the approval of any other proposal. If the Business Combination Proposal is not approved, the other proposals (except the Adjournment Proposal) will not be presented to the stockholders for a vote.

Tailwind’s Directors and Executive Officers Have Financial Interests in the Business Combination

Certain of Tailwind’s executive officers and directors may have interests in the Business Combination that may be different from, or in addition to, the interests of Tailwind’s stockholders. It is possible that the Sponsor and its affiliates may earn a positive rate of return on their investment, even if other stockholders of Tailwind experience a negative rate of return in New Nuburu. Accordingly, the Sponsor may benefit from the completion of the Business Combination, even in a scenario where other Tailwind stockholders may not similarly benefit. The Sponsor is thereby incentivized to complete an acquisition, even if it might be of a less-favorable target company or on terms less favorable to Tailwind’s stockholders, rather than liquidate. The members of the Tailwind board of directors were aware of and considered these interests, among other matters, when they approved the Business Combination Agreement and recommended that Tailwind stockholders approve the proposals required to effect the Business Combination. See “The Business Combination — Interests of Tailwind’s Directors and Officers in the Business Combination.”

Conditions to the Business Combination

Conditions to Each Party’s Obligations

The obligation of Tailwind and Nuburu to consummate the Business Combination is subject to certain closing conditions, including, but not limited to, (i) the absence of any order, law or other legal restraint or prohibition issued by any court of competent jurisdiction or other governmental entity of competent jurisdiction enjoining or prohibiting the consummation of the Business Combination, (ii) the effectiveness of the registration statement of which this proxy statement/prospectus forms a part in accordance with the provisions of the Securities Act, (iii) the required approvals of Tailwind’s stockholders, (iv) the required approvals of Nuburu’s stockholders and(v) Tailwind having at least $5,000,001 of net tangible assets (as determined in accordance with Rule 3a51-1(g)(1) of the Exchange Act) remaining immediately after the Closing.

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Conditions to Tailwind and Merger Sub’s Obligations

The obligation of Tailwind and Merger Sub to consummate the Business Combination is subject to certain closing conditions, including, but not limited to, (i) certain representations and warranties of Nuburu being true and correct, (ii) Nuburu’s performance and compliance with the agreements and covenants required by the Business Combination Agreement, (iii) the absence of any event, change, development, or other occurrence that would reasonably be expected to have a material adverse effect on Nuburu or its business or materially delay or impede Nuburu’s performance of its obligations under the Business Combination Agreement and (iv) the delivery of certain ancillary documentation to the Business Combination Agreement.

Conditions to Nuburu’s Obligations

The obligation of Nuburu to consummate the Business Combination is subject to certain closing conditions, including, but not limited to, (i) certain representations and warranties of Tailwind and Merger Sub being true and correct, (ii) Tailwind and Merger Sub’s performance and compliance with the agreements and covenants required by the Business Combination Agreement, (iii) the absence of any event, change, development, or other occurrence that would reasonably be expected to have a material adverse effect on Tailwind or its business or materially delay or impede Tailwind or Merger Sub’s performance of their obligations under the Business Combination Agreement, (iv) the delivery of certain ancillary documentation to the Business Combination Agreement, (v) Tailwind’s stock remaining listed on a national securities exchange and (vi) the approval by a national securities exchange of New Nuburu’s initial listing application in connection with the Business Combination.

Termination

The Business Combination Agreement may be terminated under certain customary and limited circumstances prior to the Closing, including, but not limited to, (i) by mutual written consent of Tailwind and Nuburu, (ii) by Tailwind if the representations and warranties of Nuburu are not true and correct or if Nuburu fails to perform any covenant or agreement set forth in the Business Combination Agreement such that certain conditions to closing cannot be satisfied and the breach or breaches of such representations or warranties or the failure to perform such covenants or agreements, as applicable, are not cured or cannot be cured within certain specified time periods, (iii) by Nuburu if the representations and warranties of Tailwind or Merger Sub are not true and correct or if any of Tailwind or Merger Sub fails to perform any covenant or agreement set forth in the Business Combination Agreement such that certain conditions to closing cannot be satisfied and the breach or breaches of such representations or warranties or the failure to perform such covenants or agreements, as applicable, are not cured or cannot be cured within certain specified time periods, (iv) subject to certain limited exceptions, by either Tailwind or Nuburu if the Business Combination is not consummated by March 9, 2023, (v) by either Tailwind or Nuburu if certain required approvals are not obtained from Tailwind stockholders after the conclusion of a meeting of Tailwind’s stockholders held for such purpose at which such stockholders voted on such approvals, (vi) by Tailwind if Nuburu has not delivered to Tailwind a written consent of the Nuburu stockholders approving the Business Combination and the transactions contemplated thereby (including the Merger) within five business days of the registration statement of which this proxy statement/prospectus forms a part being declared effective under the Securities Act, and (vii) by Tailwind if, prior to obtaining written consent of the Nuburu stockholders approving the Business Combination and the transactions contemplated thereby (including the Merger), if Nuburu’s board or any committee thereof fails to make, changes or withdraws its recommendation of the Business Combination and the transactions contemplated thereby (including the Merger) or makes any public statement inconsistent with its recommendation.

Other Agreements

Tailwind Sponsor Support Agreement

Tailwind and the Sponsor, concurrently with the execution and delivery of the Business Combination Agreement, entered into the Sponsor Support Agreement, pursuant to which the Sponsor agreed, among other things, (A) to vote (or execute and return an action by written consent), or cause to be voted at the Tailwind Special Meeting all of its Class B Common Stock or any other voting securities of Tailwind which it holds, owns, or is entitled to vote, in favor of the approval and adoption of the Business Combination Agreement and approval of the Business Combination, including the Merger, (B) not to redeem any of the Class B Common Stock pursuant to or in connection with any vote for the approval of any extension of the deadline for Tailwind to consummate its initial business combination, and (C) to forfeit the shares of New Nuburu Common Stock held by the Sponsor other than certain retained shares. In connection with the consummation of the transactions contemplated by the Business Combination Agreement, the Sponsor

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agrees that, upon and subject to the occurrence of the Closing, the Sponsor shall automatically cancel, without any further action by the Sponsor or any other Person, all of the Private Placement Warrants that are held by the Sponsor. The Sponsor also waived, for no consideration, its right to receive the Preferred Stock Issuance, other than with respect to 1,000,000 shares of New Nuburu Series A Preferred Stock.

Tailwind Sponsor Letter Agreement Amendment

Concurrently with the Closing, (i) Tailwind, (ii) Tailwind Sponsor, (iii) Nuburu and (iv) each of the Insiders, will enter into an amendment to that certain Sponsor Letter Agreement, dated as of September 3, 2020, pursuant to which, among other things, the lock-up restrictions thereunder will be amended and restated in their entirety, to provide that the Insiders shall not transfer any Founder Shares (as defined therein) (A) if the completion of an initial Business Combination occurs prior to March 30, 2023, until the earliest of (i) nine (9) months following the completion of an initial Business Combination and (ii) September 30, 2023 and (B) if the completion of an initial Business Combination occurs on or after March 30, 2023, six (6) months following the completion of an initial Business Combination.

Transaction Support Agreements

Concurrently with the execution of the Business Combination Agreement, Tailwind, Nuburu, and certain stockholders of Nuburu entered into the Stockholder Support Agreement, pursuant to which such stockholders of Nuburu have agreed, among other things, to vote all of their shares of Nuburu Common Stock and Nuburu Preferred Stock in favor of the Business Combination Agreement and the Business Combination, including the Merger, and to waive all of their right in respect of the Preferred Stock Issuance (other than with respect to any shares underlying the Company Notes). The Nuburu stockholders party to the Stockholder Support Agreement own a sufficient amount of outstanding Nuburu stock, collectively, to approve the Business Combination Agreement and the Business Combination if they vote for approval of such transactions, even if every other Nuburu stockholder votes against such transactions.

Registration Rights and Lock-up Agreements

Concurrently with the execution of the Business Combination Agreement, Tailwind and the Holders (as defined in the Registration Rights and Lock-Up Agreement (as defined below)) entered into an Amended and Restated Registration Rights and Lock-Up Agreement (the “Registration Rights and Lock-Up Agreement”), which amends and restates in its entirety the Registration and Stockholder Rights Agreement between Tailwind and the Sponsor, dated September 9, 2020 and obligates Tailwind to file a registration statement to register the resale of certain shares of New Nuburu Common Stock held by the Holders (as defined therein).

Preferred Stock Sale Option Agreement

Concurrently with the execution and delivery of the Registration Rights and Lock-Up Agreement, Tailwind and the Anzu SPVs therein have entered into a Preferred Stock Sale Option Agreement (the “Sale Option Agreement”). Pursuant to the terms of the Sale Option Agreement, in the event an Anzu SPV transfers any shares of New Nuburu Common Stock beneficially owned or owned of record by such holder prior to the expiration of the lock-up period applicable to such holder in a Permitted Transfer (as defined therein), such holder must notify the Post-Combination Company of the Permitted Transfer, whereupon, the Post-Combination Company has the right, but not the obligation, to cause such holder to use up to 2/3 of the gross proceeds of the Permitted Transfer to purchase New Nuburu Series A Preferred Stock from New Nuburu at a price equal to $10.00 per share (as adjusted for stock splits, stock dividends, reorganizations, recapitalizations and the like).

Lincoln Park Purchase Agreement and Registration Rights Agreement

In connection with the execution of the Business Combination Agreement, Tailwind, Nuburu and Lincoln Park have concurrently entered into the Lincoln Park Purchase Agreement to establish a committed funding agreement. In conjunction with the entry into such purchase agreement, Tailwind, Nuburu and Lincoln Park have also entered into a Registration Rights Agreement to grant certain registration rights to Lincoln Park.

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Listing

Tailwind’s units, Class A Common Stock and public warrants are publicly traded on the NYSE under the symbols “TWND.U,” “TWND” and “TWND WS,” respectively. Following the Closing, New Nuburu (formerly Tailwind) will continue to have its New Nuburu Common Stock and public warrants traded under the symbols “BURU” and “BURU WS” respectively. Tailwind warrant holders and those stockholders who do not elect to have their shares redeemed need not deliver their shares of Class A Common Stock or warrant certificates to Tailwind or Tailwind’s transfer agent and they will remain outstanding. New Nuburu does not intend to apply to list the New Nuburu Series A Preferred Stock on any securities exchange or nationally recognized trading system, including the NYSE.

Comparison of Stockholders’ Rights

Following the Business Combination, the rights of public holders who become New Nuburu stockholders in the Business Combination will no longer be governed by the Pre-Closing Tailwind Certificate of Incorporation and instead will be governed by the Post-Closing New Nuburu Certificate of Incorporation. See “Comparison of Stockholders’ Rights.”

Risk Factors

You should consider all the information contained in this proxy statement/prospectus in deciding how to vote for the proposals presented in the proxy statement/prospectus. In particular, you should carefully read and consider the factors described under “ —  Risk Factors Summary” and “Risk Factors.”

Risk Factors Summary

The transactions described in this proxy statement/prospectus involve various risks, and you should carefully read and consider the factors discussed under “Risk Factors.” The following is a summary of some of these risks.

Risks Relating to Our Business and Operations

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Risks Related to the Business Combination

Information about Tailwind

Tailwind is a special purpose acquisition company formed for the purpose of effecting a merger, capital stock exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses. Tailwind’s units, Class A Common Stock and public warrants are publicly traded on the NYSE under the symbols “TWND.U,” “TWND” and “TWND WS,” respectively. The mailing address of Tailwind’s principal executive office is 1545 Courtney Avenue Los Angeles, CA 90046 and the telephone number of Tailwind’s principal executive office is (646) 432-0610.

Information about Nuburu

Nuburu is a leading innovator in high-power, high-brightness blue laser technology that is focused on bringing breakthrough improvements to a broad range of high value applications including welding and 3D printing. By delivering increased speed and quality Nuburu hopes to enhance productivity for manufacturers in the e-mobility, consumer electronics, aerospace and defense and 3D printing markets.

The mailing address of Nuburu’s principal executive office is 7442 Tucson Way, Suite 130, Centennial, CO 80112, and the telephone number of Nuburu’s principal executive office is (720) 767-1400.

Ownership of New Nuburu

As of the date of this proxy statement/prospectus, there are 11,588,234 Tailwind Shares issued and outstanding, including 8,355,393 shares of Class B Common Stock. The Sponsor owns 100% of the outstanding Class B Common Stock (amounting to approximately 72.1% of the outstanding shares of Tailwind common stock). As of the date of this proxy statement/prospectus, there are an aggregate of              public warrants and 9,700,000 private placement warrants outstanding. Each whole warrant entitles the

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holder thereof to purchase one (1) share of Class A Common Stock. Therefore, as of the date of this proxy statement/prospectus (without giving effect to the Business Combination and assuming no redemptions), assuming that each outstanding warrant is exercised and one (1) share of Class A Common Stock is issued as a result of such exercise, the Tailwind fully-diluted stock capital would be              Tailwind Shares.

Subject to the assumptions set forth under “Basis of Presentation and Glossary” in this accompanying proxy statement/prospectus, the following table illustrates varying beneficial ownership levels in New Nuburu immediately following consummation of the Business Combination, assuming the levels of redemptions by the public stockholders of Tailwind indicated:

Common Stock:

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Preferred Stock:

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SUMMARY HISTORICAL FINANCIAL INFORMATION OF TAILWIND

The following table shows summary historical financial information of Tailwind for the periods and as of the dates indicated.

The summary historical financial information of Tailwind as of December 31, 2021 and for the year ended December 31, 2021 was derived from the audited historical consolidated financial statements of Tailwind included elsewhere in this proxy statement/prospectus. The summary historical financial information of Tailwind as of June 30, 2022 and for the six months ended June 30, 2022 was derived from the unaudited interim historical consolidated financial statements of Tailwind included elsewhere in this proxy statement/prospectus.

The following summary historical financial information should be read together with the financial statements and accompanying notes and “Tailwind Management’s Discussion and Analysis of Financial Condition and Results of Operations” appearing elsewhere in this proxy statement/prospectus. The summary historical financial information in this section is not intended to replace Tailwind’s consolidated financial statements and the related notes. Tailwind’s historical results are not necessarily indicative of Tailwind’s future results.

As explained elsewhere in this proxy statement/prospectus, the financial information contained in this section relates to Tailwind, prior to and without giving pro forma effect to the impact of the Business Combination and, as a result, the results reflected in this section may not be indicative of the results of New Nuburu going forward.

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TAILWIND ACQUISITION CORP.

STATEMENT OF OPERATIONS DATA

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TAILWIND ACQUISITION CORP.

BALANCE SHEET DATA

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SUMMARY HISTORICAL CONSOLIDATED FINANCIAL INFORMATION OF NUBURU

The following table shows summary historical financial information of Nuburu for the periods and as of the dates indicated.

The summary historical financial information of Nuburu as of December 31, 2021 and 2020, and for the years ended December 31, 2021 and 2020, was derived from the audited historical consolidated financial statements of Nuburu included elsewhere in this proxy statement/prospectus. The summary historical financial information of Nuburu as of June 30, 2022, and for the six months ended June 30, 2022 and 2021, was derived from the unaudited interim historical financial statements of Nuburu included elsewhere in this proxy statement/prospectus.

The following summary historical financial information should be read together with the consolidated financial statements and accompanying notes and “Nuburu’s Management’s Discussion and Analysis of Financial Condition and Results of Operations” appearing elsewhere in this proxy statement/prospectus. The summary historical financial information in this section is not intended to replace Nuburu’s consolidated financial statements and the related notes. Nuburu’s historical results are not necessarily indicative of Nuburu’s future results.

As explained elsewhere in this proxy statement/prospectus, the financial information contained in this section relates to Nuburu, prior to and without giving pro forma effect to the impact of the Business Combination and, as a result, the results reflected in this section may not be indicative of the results of New Nuburu going forward.

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SUMMARY UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION

The following summary unaudited pro forma combined financial data (the “summary pro forma data”) gives effect to the transactions contemplated by the Business Combination.

The Business Combination is expected to be accounted for as a reverse recapitalization in accordance with GAAP because Nuburu has been determined to be the accounting acquirer under each of the redemption scenarios presented. Under this method of accounting, Tailwind, which is the legal acquirer, will be treated as the accounting acquiree for financial reporting purposes and Nuburu, which is the legal acquiree, will be treated as the accounting acquirer. Accordingly, the consolidated assets, liabilities and results of operations of Nuburu will become the historical financial statements of New Nuburu, and Tailwind’s assets, liabilities and results of operations will be consolidated with Nuburu’s beginning on the acquisition date. For accounting purposes, the financial statements of New Nuburu will represent a continuation of the financial statements of Nuburu with the Business Combination being treated as the equivalent of Nuburu issuing stock for the net assets of Tailwind, accompanied by a recapitalization. The net assets of Tailwind will be stated at historical costs and no goodwill or other intangible assets will be recorded. Operations prior to the Business Combination will be presented as those of Nuburu in future reports of New Nuburu.

The summary pro forma data have been derived from, and should be read in conjunction with, the unaudited pro forma combined financial information of New Nuburu appearing elsewhere in this proxy statement/prospectus and the accompanying notes. The unaudited pro forma combined financial information is based upon, and should be read in conjunction with, the historical consolidated financial statements of Tailwind and Nuburu and related notes included in this proxy statement/ prospectus. The summary pro forma data is for illustrative purposes only. The financial results may have been different had the companies always been combined. You should not rely on the summary pro forma data as being indicative of the historical results that would have been achieved had the companies always been combined or the future results that the combined entity will experience. Tailwind and Nuburu have not had any historical relationship prior to the transactions. Accordingly, no pro forma adjustments were required to eliminate activities between the companies.

The unaudited pro forma condensed combined financial information contained herein assumes that the Tailwind stockholders approve the Business Combination. Pursuant to the Pre-Closing Tailwind Certificate of Incorporation, Tailwind’s public stockholders may elect to redeem their public shares for cash even if they approve the Business Combination. Tailwind cannot predict how many of its public stockholders will exercise their right to redeem their Tailwind Class A Common Stock for cash. The unaudited pro forma condensed combined financial information has been prepared assuming three redemption scenarios after giving effect to the Business Combination, as follows:

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The three alternative levels of redemptions assumed in the unaudited pro forma condensed combined balance sheet and statement of operations are based on the assumption that there are no adjustments for the outstanding public or private placement warrants issued by Tailwind as such securities are not exercisable until 30 days after the Closing.

If the actual facts are different than these assumptions, then the amounts and shares outstanding in the unaudited pro forma condensed combined financial information will be different.

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This proxy statement/prospectus includes forward-looking statements regarding, among other things, the plans, strategies and prospects, both business and financial, of Tailwind and Nuburu. These statements are based on the beliefs and assumptions of the management of Tailwind and Nuburu. Although Tailwind and Nuburu believe that their respective plans, intentions and expectations reflected in or suggested by these forward-looking statements are reasonable, neither Tailwind nor Nuburu can assure you that either will achieve or realize these plans, intentions or expectations. Forward-looking statements are inherently subject to risks, uncertainties and assumptions. Generally, statements that are not historical facts, including statements concerning possible or assumed future actions, business strategies, events or results of operations, are forward-looking statements. These statements may be preceded by, followed by or include the words “believes,” “estimates,” “expects,” “projects,” “forecasts,” “may,” “will,” “should,” “seeks,” “plans,” “scheduled,” “anticipates,” “possible,” “continue,” “might,” “potential,” “intends” or similar expressions. Forward-looking statements contained in this proxy statement/prospectus include, but are not limited to, statements about Tailwind and Nuburu prior to the consummation of the Business Combination, and of New Nuburu following the Business Combination, with respect to: