0001213900-26-017485 Sample Contracts

UNDERWRITING AGREEMENT
Underwriting Agreement • February 17th, 2026 • Dynamix Corp IV • Blank checks • New York

The undersigned, Dynamix Corporation IV, a Cayman Islands exempted company (the “Company”), hereby confirms its agreement with Cohen & Company Capital Markets, a division of Cohen & Company Securities, LLC (the “Representative”) and with the other underwriters named on Schedule A hereto (if any), for which the Representative is acting as representative (the Representative and such other underwriters being collectively referred to herein as the “Underwriters” or, each underwriter individually, an “Underwriter,” provided that, if only the Representative is listed on such Schedule A, any references to Underwriters shall refer exclusively to the Representative) as follows:

Dynamix Corporation IV
Administrative Services Agreement • February 17th, 2026 • Dynamix Corp IV • Blank checks

This letter agreement by and between Dynamix Corporation IV (the “Company”) and Volta Tread LLC (the “Services Provider”), an affiliate of our sponsor, DynamixCore Holdings IV, LLC (“Sponsor”), dated as of the date hereof, will confirm our agreement that, commencing on the date the securities of the Company are first listed on The New York Stock Exchange (the “Listing Date”), pursuant to a Registration Statement on Form S-1 and prospectus filed with the U.S. Securities and Exchange Commission (the “Registration Statement”) and continuing until the earlier of the consummation by the Company of an initial business combination and the Company’s liquidation (in each case as described in the Registration Statement) (such earlier date hereinafter referred to as the “Termination Date”):

Insert Date] Dynamix Corporation IV 1980 Post Oak Blvd., Suite 100 PMB 6373 Houston, TX 77056
Underwriting Agreement • February 17th, 2026 • Dynamix Corp IV • Blank checks

This letter (this “Letter Agreement”) is being delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered into by and between Dynamix Corporation IV, a Cayman Islands exempted company (the “Company”), and Cohen & Company Capital Markets, a division of Cohen & Company Securities, LLC as the representative (the “Representative”) of the underwriters (the “Underwriters”), relating to an underwritten initial public offering (the “Public Offering”) of up to 20,125,000 of the Company’s units (including up to 2,625,000 units which may be purchased to cover over-allotments, if any) (the “Units”), each comprised of one Class A ordinary share, par value $0.0001 per share, of the Company (the “Class A Ordinary Shares”) and one-third of one redeemable warrant (each whole warrant, a “Warrant”). Each Warrant entitles the holder thereof to purchase one Class A Ordinary Share at a price of $11.50 per share, subject to adjustment. The Units shall be sold in the