8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THESECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): June9, 2025

DUNE ACQUISITION CORPORATION II

(Exact name of registrant as specified in its charter)

700 S. Rosemary Avenue, Suite 204

West Palm Beach, FL 33401

(Address of principal executive offices, including zip code)

Registrant’s telephone number, including area code: (917) 742-1904

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:

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

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

On June 9, 2025, Dune Acquisition Corporation II (the “Company”) issued a press release, a copy of which is attached as Exhibit 99.1 to this Current Report on Form 8-K, announcing that the holders of the Company’s units (the “Units”) may elect to separately trade the Class A ordinary shares, par value $0.0001 per share (the “Class A Shares”), and warrants (the “Warrants”) included in the Units commencing on or about June 12, 2025. Each Unit consists of one Class A Share and three-quarters of one redeemable Warrant, each whole Warrant exercisable to purchase one Class A Ordinary Share. Any Units not separated will continue to trade on The Nasdaq Stock Market (“Nasdaq”) under the symbol “IPODU”, and the Class A Shares and Warrants will separately trade on Nasdaq under the symbols “IPOD” and “IPODW”, respectively. No fractional Warrants will be issued upon separation of the Units and only whole Warrants will trade. Holders of Units will need to have their brokers contact Continental Stock Transfer & Trust Company, the Company’s transfer agent, in order to separate the Units into Class A Shares and Warrants.

EXHIBIT INDEX

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.

Exhibit 99.1

Dune Acquisition Corporation II Announces the Separate Trading of its Class A Ordinary Shares and Warrants, Commencing June 12, 2025

New York, NY, June 09, 2025 (GLOBE NEWSWIRE) -- Dune Acquisition Corporation II (Nasdaq: IPODU) (the “Company”) today announced that, commencing June 12, 2025, holders of the units sold in the Company’s initial public offering may elect to separately trade shares of the Company’s Class A ordinary shares and warrants included in the units.

No fractional warrants will be issued upon separation of the units and only whole warrants will trade. The Class A ordinary shares and warrants that are separated will trade on The Nasdaq Stock Market under the symbols “IPOD” and “IPODW,” respectively. Those units not separated will continue to trade on The Nasdaq Stock Market under the symbol “IPODU.” Holders of units will need to have their brokers contact Continental Stock Transfer & Trust Company, the Company’s transfer agent, in order to separate the units into Class A ordinary shares and warrants.

Dune Acquisition Corporation II was founded by its Chief Executive Officer, Carter Glatt. The Company is a blank check company whose business purpose is to effect a merger, amalgamation, share capital exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses. While the Company may pursue an initial business combination target in any industry or geographic region, the Company intends to focus its search for an initial business combination on companies within the software as a service, artificial intelligence, medtech or asset management and consultancy sectors.

Clear Street acted as sole book-runner of the offering.

The offering was made only by means of a prospectus. When available, copies of the prospectus relating to this offering may be obtained from Clear Street, Attn: Syndicate Department, 150 Greenwich Street, 45th Floor, New York, NY 10007, by email at ecm@clearstreet.io, or from the SEC website at www.sec.gov.

A registration statement relating to these securities was declared effective by the U.S. Securities and Exchange Commission (the “SEC”) on May 6, 2025. This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

Cautionary Note Concerning Forward-Looking Statements

This press release contains statements that constitute “forward-looking statements,” including with respect to the search for an initial business combination. No assurance can be given that the proceeds of the offering will be used as indicated. Forward-looking statements are subject to numerous conditions, many of which are beyond the control of the Company, including those set forth in the Risk Factors section of the Company’s registration statement and prospectus for the initial public offering filed with the SEC. Copies are available on the SEC’s website, www.sec.gov. The Company undertakes no obligation to update these statements for revisions or changes after the date of this release, except as required by law.

Contact

Carter Glatt

Chief Executive Officer

Dune Acquisition Corporation II

ir@duneacq.com

(917) 742-1904