Surfside Acquisition Inc.

02/23/2026 | Press release | Distributed by Public on 02/23/2026 20:09

Initial Statement of Beneficial Ownership (Form 3)

FORM 3
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Peres Mark Wayne
2. Date of Event Requiring Statement (Month/Day/Year)
02/19/2026
3. Issuer Name and Ticker or Trading Symbol
DEEP FISSION, INC. [NONE]
(Last) (First) (Middle)
C/O DEEP FISSION, INC., 2001 ADDISON STREET, SUITE 300
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chief Nuclear Officer
5. If Amendment, Date Original Filed (Month/Day/Year)
(Street)
BERKELEY, CA 94704
6. Individual or Joint/Group Filing (Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City) (State) (Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)
2. Amount of Securities Beneficially Owned
(Instr. 4)
3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)
4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Common Stock 86,607(1) D
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.
Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)
2. Date Exercisable and Expiration Date
(Month/Day/Year)
3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)
4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)
6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Peres Mark Wayne
C/O DEEP FISSION, INC.
2001 ADDISON STREET, SUITE 300
BERKELEY, CA 94704
Chief Nuclear Officer

Signatures

/s/ Jon Gordon as attorney-in-Fact for Mark Peres 02/23/2026
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Reflects shares of common stock received in connection with the merger completed in September 2025. A portion of the shares are subject to the Company's right of repurchase at cost upon termination of service, which right lapses as the shares vest.

Remarks:
Exhibit 24: Power of Attorney attached herewith.
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, See Instruction 6 for procedure. Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.
Surfside Acquisition Inc. published this content on February 23, 2026, and is solely responsible for the information contained herein. Distributed via EDGAR on February 24, 2026 at 02:09 UTC. If you believe the information included in the content is inaccurate or outdated and requires editing or removal, please contact us at [email protected]