UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (MARK ONE) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2025 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-42607 DUNE ACQUISITION CORPORATION II (Exact Name of Registrant as Specified in Its Charter) Cayman Islands N/A (State or othe ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (MARK ONE) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 (Address of principal executive offices) | (917) 742-1904 | | --- | (Registrant's telephone number, including area code) Securities registered pursuant to Section 12(b) of the Act: For the tran ...

As filed with the U.S. Securities and Exchange Commission on April 29, 2025. Registration No. 333-285639 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ____________________ AMENDMENT NO. 2 TO FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 ____________________ DUNE ACQUISITION CORPORATION II (Exact name of registrant as specified in its charter) ____________________ Cayman Islands 6770 N/A (State or other jurisdiction of incorporation or organization) (Primary Stand ...

As filed with the U.S. Securities and Exchange Commission on March 25, 2025. Registration No. 333-285639 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ____________________ AMENDMENT NO. 1 TO FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 ____________________ DUNE ACQUISITION CORPORATION II (Exact name of registrant as specified in its charter) ____________________ Cayman Islands 6770 N/A (State or other jurisdiction of incorporation or organization) (Primary Stand ...

As filed with the U.S. Securities and Exchange Commission on March 7, 2025. Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ____________________ FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 ____________________ DUNE ACQUISITION CORPORATION II (Exact name of registrant as specified in its charter) ____________________ Cayman Islands 6770 N/A (State or other jurisdiction of incorporation or organization) (Primary Standard Industrial Classificat ...