UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

~~Pursuant~~PURSUANT toTO ~~Section~~SECTION 13 orOR 15(dD) ofOF THE SECURITIES EXCHANGE ACT OF 1934

~~the~~Date ~~Securities~~of ~~Exchange~~Report ~~Act~~(Date of ~~1934~~earliest event reported): June 10, 2026

~~Date of~~M3-BRIGADE ~~Report~~ACQUISITION V CORP. (~~Date~~Exact name of ~~earliest~~registrant ~~event~~as ~~reported):~~specified ~~February 18,~~in ~~2026~~its charter)

M3-Brigade Acquisition V Corp.

Cayman Islands		001-42171		98-1781141
(State or other jurisdiction of incorporation)		(Commission File Number)		(I.R.S. Employer Identification No.)

(Exact name of registrant as specified in its charter)

1700 Broadway, 19th Floor New York, New York		10019
(Address of principal executive offices)		(Zip Code)

~~Cayman~~(212) ~~Islands~~202-2200

(~~State~~Registrant’s ortelephone ~~other~~number, ~~jurisdiction~~including area ~~of incorporation~~code)

001-42171		98-1781141
(Commission File Number)		(IRS Employer Identification No.)

1700 Broadway, 19th Floor, New York, New York 10019

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: (212) 202-2200

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K ~~filing~~ is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐☒ Written ~~communications~~communication pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement ~~communication~~communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement ~~communication~~communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Units, each consisting of one Class A ordinary share and one-half of one redeemable warrant	MBAVU	The Nasdaq Stock Market LLC
Class A ordinary share, par value $0.0001 per share	MBAV	The Nasdaq Stock Market LLC
Units, each consisting of one Class A ordinary share and one-half of one redeemable warrant	MBAVU	The Nasdaq Stock Market LLC
Warrants, each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50 per share	MBAVW	The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (~~17 CFR~~ §230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 ~~(17~~ ~~CFR~~ (§240.12b-2 of this chapter).

Emerging growth company ☒

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 13(a) of the Exchange Act. ☐

Item 18.01. Other ~~Entry into a Material Definitive Agreement~~Events.

OnPostponement February 18, 2026, M3-Brigade Acquisition V Corp. (the “Company”) issued a promissory note (the “Note”) to MI7 Sponsor, LLC (the “Sponsor”), the Company’s sponsor, pursuant to which the Company can borrow up to an aggregate principal amount of ~~$2,000,000~~Meeting ~~from~~– ~~the~~Additional ~~Sponsor.~~Definitive OnProxy ~~February 18, 2026, the Company borrowed $600,000 under the Note. The proceeds of the~~Solicitation ~~Note will be used to provide the Company with general working capital.~~Materials

~~The~~On ~~Note~~June ~~bears~~10, no2026, ~~interest and~~M3-Brigade isAcquisition ~~payable~~V inCorp. (the ~~full~~“Company”) ~~upon~~announced ~~the~~that ~~consummation~~it ofhas ~~the~~postponed ~~Company’s~~its ~~initial~~extraordinary ~~business~~general ~~combination~~meeting of shareholders (the “~~Maturity Date~~Meeting”). ~~A failure~~ to ~~pay~~consider ~~the~~and ~~principal~~vote on the ~~Maturity~~previously ~~Date~~announced ~~shall~~proposed bebusiness ~~deemed~~combination ~~an event of default, in which case~~ (the ~~Note~~“Business ~~may~~Combination”) ~~be accelerated. If~~between the Company ~~does~~and ~~not~~ReserveOne, ~~consummate an initial business combination~~Inc., ~~the~~a ~~Note~~Delaware ~~will~~corporation ~~be repaid solely to the extent the Company has funds available outside its trust account established in connection with the Company’s initial public offering~~(“ReserveOne”).

The ~~description~~Meeting, ofwhich ~~the~~was originally scheduled to ~~Note~~be ~~does~~held ~~not~~on ~~purport~~June to15, be2026, ~~complete~~at 11:00 a.m. Eastern Time, has been postponed and is ~~subject~~now scheduled to be held on June 18, ~~and~~2026 ~~qualified~~at in12:00 ~~its~~p.m. Eastern ~~entirety~~Time. byThe ~~reference~~Meeting location has not changed and will continue to, ~~the~~be ~~Note,~~held aat ~~copy~~the office of ~~which~~Troutman isPepper ~~attached~~Locke LLP, located at ~~hereto~~875 asThird ~~Exhibit~~Ave, ~~10.1~~17th Floor, New York, New York 10022, and issimultaneously ~~incorporated~~via ~~herein~~live bywebcast ~~reference~~at https://www.cstproxy.com/m3brigadev/2026.

~~Item~~The ~~2.03~~record ~~Creation~~date for the Meeting remains the close of abusiness ~~Direct~~on ~~Financial~~May ~~Obligation~~7, or2026, anand ~~Obligation~~no ~~under~~changes anhave ~~Off-Balance~~been ~~Sheet~~made ~~Arrangement~~to the proposals to be considered at the Meeting or to the recommendations of athe ~~Registrant~~Company’s board of directors with respect to the proposals to be considered at the Meeting.

The ~~information~~Company ~~set~~has ~~forth~~decided to postpone the Meeting to provide its shareholders with additional time to consider the Business Combination and the proposals described in ~~Item~~the ~~1.01~~Company’s ofdefinitive ~~this~~proxy ~~Current~~statement/prospectus ~~Report~~and onto ~~Form~~allow ~~8-K~~shareholders isadditional ~~incorporated~~time byto ~~reference~~submit ~~into~~their ~~this~~proxies ~~Item~~and 2for the Company to continue its outreach to shareholders whose votes have not yet been received.~~03.~~

~~Item~~In 9connection with the postponement of the Meeting, the Company is also extending the deadline for holders of the Company’s Class A ordinary shares, par value $0.010001 ~~Financial~~per ~~Statements~~share (“Class A Ordinary Shares”), sold in the Company’s initial public offering (the “Public Shares”) to exercise their redemption rights. The deadline for holders of the Company’s Public Shares to submit redemption requests to the Company’s transfer agent, which was previously 5:00 p.m., Eastern Time, on June 11, 2026, has been extended to 5:00 p.m., Eastern Time, on June 16, 2026 (two business days prior to the vote at the Meeting). Shareholders who wish to exercise their redemption rights must do so in accordance with the instructions set forth in the Company’s definitive proxy statement/prospectus, as supplemented, and ~~Exhibits~~should contact their broker or the Company’s transfer agent as soon as possible to ensure that their redemption instructions are received by the new deadline.

~~(d)~~Shareholders ~~Exhibits:~~who have already submitted a proxy voting their shares do not need to take any action as a result of the postponement and their proxies will remain valid and will be voted at the postponed Meeting unless properly revoked. Shareholders who have not yet voted or who wish to change their vote are strongly encouraged to do so as soon as possible in the manner described in the Company’s proxy materials.

10.1		Promissory Note, dated February 18, 2026
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

A copy of the press release issued by the Company on June 10, 2026 announcing the postponement of the Meeting and the extension of the redemption deadline is filed as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

~~SIGNATURE~~Additional Information and Where to Find It

~~Pursuant~~In toconnection with the ~~requirements~~proposed ofbusiness combination among the ~~Securities~~Company, ReserveOne, Inc. (“ReserveOne”), ReserveOne Holdings, Inc. (“Pubco”) and certain other parties (the “Business Combination”), Pubco and ReserveOne have filed with the Securities and Exchange ~~Act~~Commission (“SEC”) ofa ~~1934~~registration statement on Form S-4 (as may be amended or supplemented from time to time, the ~~registrant~~“Registration Statement”), ~~has~~which ~~duly~~includes ~~caused~~a ~~this~~preliminary ~~report~~proxy statement of the Company and a prospectus in connection with the Business Combination as well as other relevant documents concerning the Business Combination. The Registration Statement was declared effective on May 13, 2026 and the prospectus/proxy statement was first mailed to bethe ~~signed~~Company’s stockholders on ~~its~~May 21, ~~behalf~~2026. INVESTORS AND SHAREHOLDERS OF THE COMPANY ARE ADVISED TO READ THE DEFINITIVE PROXY STATEMENT, THE PROSPECTUS AND ALL OTHER RELEVANT DOCUMENTS FILED OR THAT HAS BEEN FILED WITH THE SEC IN CONNECTION WITH THE BUSINESS COMBINATION BECAUSE THEY CONTAIN IMPORTANT INFORMATION. HOWEVER, THIS DOCUMENT WILL NOT CONTAIN ALL THE INFORMATION THAT SHOULD BE CONSIDERED CONCERNING THE BUSINESS COMBINATION. IT IS ALSO NOT INTENDED TO FORM THE BASIS OF ANY INVESTMENT DECISION OR ANY OTHER DECISION IN RESPECT OF THE BUSINESS COMBINATION. Shareholders and other interested persons are able to obtain free copies of the definitive proxy statement, the Registration Statement and other documents filed by the Company ~~undersigned~~with ~~hereunto~~the ~~duly~~SEC ~~authorized~~containing information about the Company, Pubco and/or ReserveOne that will be incorporated by reference therein, without charge at the SEC’s website at www.sec.gov. The Company’s shareholders will also be able to obtain a copy of such documents, without charge, from the Company by directing a written request to: M3-Brigade Acquisition V Corp., 1700 Broadway, 19th Floor, New York, New York 10019, or from ReserveOne by directing a request to [email protected].

	M3-Brigade Acquisition V Corp.
Date: February 18, 2026	By:	/s/ Robert Rivas Collins
		Name:	Robert Rivas Collins
		Title:	Chief Executive Officer

Participants in the Solicitation

2Each of the Company, ReserveOne, ReserveOne Holdings, Inc., and their respective directors executive officers and certain other members of management and employees may be deemed under SEC rules to be participants in the solicitation of proxies from the Company’s shareholders in connection with the Business Combination. Information regarding the persons who may be considered participants in the solicitation of proxies in connection with the Business Combination, including a description of their direct or indirect interests, by security holdings or otherwise, is set forth in the proxy statement/prospectus and other relevant materials filed or that will be filed with the SEC. Information regarding the directors and executive officers of the Company is set forth in (i ) Part III, Item 10. Directors, Executive Officers and Corporate Governance of the Company’s Annual Report on Form 10-K and (ii) the Company’s Current Reports on Form 8-K filed with the SEC. Information regarding the identity of all potential participants, and their direct and indirect interests, by security holdings or otherwise, will be set forth in the proxy statement/prospectus and other relevant materials filed with the SEC. These documents can be obtained free of charge from the sources indicated above.

No Offer or Solicitation

This communication is for informational purposes only and is not intended to and does not constitute an offer to subscribe for, buy or sell, the solicitation of an offer to subscribe for, buy or sell or an invitation to subscribe for, buy or sell any securities or the solicitation of any vote or approval in any jurisdiction pursuant to or in connection with the Business Combination or otherwise, nor will there be any sale, issuance or transfer of securities in any jurisdiction in contravention of applicable law. No offer of securities will be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended and otherwise in accordance with applicable law.

Cautionary Statement Regarding Forward-Looking Statements

Certain statements herein and the documents incorporated herein by reference may constitute “forward-looking statements”, which statements involve inherent risks and uncertainties.

Examples of forward-looking statements include, but are not limited to, statements with respect to the Business Combination. Such statements include expectations, hopes, beliefs, intentions, plans, prospects, financial results of strategies regarding the Company, ReserveOne, Pubco, the Business Combination and statements regarding the anticipated benefits and timing of the completion of the Business Combination, the price and volatility of cryptocurrencies, the growing prominence of cryptocurrencies, the macro and political conditions surrounding cryptocurrencies, plans and use of proceeds, objectives of management for future operations of the Company, ReserveOne and Pubco, expected operating costs of Pubco, the Company, ReserveOne and their respective subsidiaries, the upside potential and opportunity for investors, the Company’s plan for value creation and strategic advantages, market site and growth opportunities, regulatory conditions, competitive position and the interest of other corporations in similar business strategies, technological and market trends, future financial condition and performance and expected financial impacts of the Business Combination, the satisfaction of closing conditions to the Business Combination and the level of redemptions of the Company’s public shareholders, and ReserveOne’s and Pubco’s expectations, intentions, strategies, assumptions or beliefs about future events, results at operations or performance or that do not solely relate to historical or current facts. These forward-looking statements generally are identified by the words “believe,” “project,” “expect,” “anticipate,” “estimate,” “intend,” “strategy,” “future,” “opportunity,” “potential,” “plan,” “may,” “should,” “will,” “would,” “will be,” “will continue,” “will likely result,” and similar expressions. Forward-looking statements are based on assumptions as of the time they are made and are subject to risks, uncertainties and other factors that are difficult to predict with regard to timing, extent, likelihood and degree of occurrence, which could cause actual results to differ materially from anticipated results expressed or implied by such forward-looking statements. Such risks, uncertainties and assumptions, include, but are not limited to: (i) the risk that the Business Combination may not be completed in a timely manner or at all; (ii) the risk related to ReserveOne’s lack of operating history as an early-stage company; (iii) risks related to ReserveOne’s anticipated business plan and strategy that ReserveOne expects to implement upon consummation of the Business Combination, including the risk that ReserveOne’s business strategy may change significantly in the future, including moving away from its currently intended focus on crypto-related activities; (iv) the failure by the parties to satisfy the conditions to the consummation of the Business Combination, including the approval of the Company’s shareholders; (v) the failure to realize the anticipated benefits of the Business Combination; (vi) the limitations on ReserveOne’s investments in certain tokens and allocations to yield generation and venture activities under securities laws; (vii) the outcome of any potential legal proceedings that may be instituted against Pubco, ReserveOne, the Company or others following announcement of the Business Combination; (viii) the level of redemptions of the Company’s public shareholders which may reduce the public float of, reduce the liquidity of the trading market of, and/or maintain the quotation, listing, or trading of the Company’s class A ordinary shares or the Pubco’s class A common stock; (iv) the failure of Pubco to obtain or maintain the listing of its securities on any stock exchange on which the Pubco’s class A common stock will be listed after closing of the Business Combination; (x) costs related to the Business Combination and as a result of Pubco becoming a public company; (xi) changes in business, market, financial, political and regulatory conditions; (xii) risks relating to ReserveOne’s anticipated operations and business, including the highly volatile nature of the price of cryptocurrencies; risks related to increased competition in the industries in which ReserveOne will operate; (xiii) risks relating to significant legal, commercial, regulatory and technical uncertainty regarding cryptocurrencies; risks related to the treatment of cryptocurrency and other digital assets for U.S. and federal, state, local and non-U.S. tax purposes; (xiv) risks that after consummation of the Business Combination, ReserveOne experiences difficulties managing its growth and expanding operations; (xv) challenges in implementing the business plan, due to lack of an operating history, operational challenges, significant competition and regulation; (xvi) being considered to be a “shell company” by any stock exchange or by the SEC; and (xvii) those risk factors discussed in documents of the Company or Pubco filed, or to be filed, with the SEC.

The foregoing list of risk factors is not exhaustive. You should carefully consider the foregoing factors and the other risks and uncertainties described in the “Risk Factors” section in the Company’s final prospectus dated as of July 31, 2024 and filed by the Company with the SEC on August 2, 2024, our Quarterly Reports on Form 10-Q, and our Annual Report on Form 10-K and the proxy statement/prospectus that will be filed by the Company and Pubco, and other documents filed or to be filed by the Company and Pubco from time to time with the SEC, including Pubco’s Form S-4 filed with the SEC on December 5, 2025, as may be amended or supplemented from time to time. These filings do or will identify and address other important risks and uncertainties that could cause actual events and results to differ materially from those contained in the forward-looking statements. There may be additional risks that neither the Company, ReserveOne or Pubco presently know or currently believe are immaterial that could also cause actual results to differ from those contained in the forward-looking statements.

Forward-looking statements speak only as of the date they are made. Readers are cautioned not to put undue reliance on forward-looking statements, and except as otherwise required by applicable law, none of the parties or any of their representatives assumes any obligation and does not intend to update or revise these forward-looking statements, whether as a result of new information, future events, or otherwise. None of the parties or any of their representatives gives any assurance that any of the Company, ReserveOne or Pubco will achieve its expectations. The inclusion of any statement in this Current Report on Form 8-K does not constitute an admission by ReserveOne, Pubco, the Company or any other person that the events or circumstances described in such statement are material.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.		Description
99.1		News Release dated June 10, 2026
104		Cover Page Interactive Data File (embedded within the Inline XBRL document).

Signature

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	M3-Brigade Acquisition V Corp.

Date: June 10, 2026	By:	/s/ Robert Rivas Collins
		Name:	Robert Rivas Collins
		Title:	Chief Executive Officer

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