EX-32.1
Published on November 14, 2025
Exhibit 32.1
CERTIFICATION OF THE PRINCIPAL EXECUTIVE OFFICER
PURSUANT TO 18 U.S.C. SECTION 1350 AS ADOPTED PURSUANT TO SECTION 906 OF THE
SARBANES-OXLEY ACT OF 2002
In connection with the Quarterly Report on Form 10-Q of Deep Fission, Inc. (the “Company”) for the quarter ended September 30, 2025, as filed with the Securities and Exchange Commission (the “Report”), pursuant to 18 U.S.C Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, I, Elizabeth Muller, the Chief Executive Officer of Deep Fission, Inc. (the “Company”) hereby certify, that, to my knowledge:
1. | The Report fully complies with the requirements of Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934, as amended; and |
2. | The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company. |
Date: November 14, 2025 | /s/ Elizabeth Muller |
| Elizabeth Muller |
| Chief Executive Officer |
| (Principal Executive Officer) |