Elizabeth Muller - 09 Dec 2025 Form 4 Insider Report for DEEP FISSION, INC.

Role
Chief Executive Officer
Signature
/s/ Jon Gordon, as Attorney-in-Fact for Elizabeth Muller
Issuer symbol
N/A
Transactions as of
09 Dec 2025
Net transactions value
$0
Form type
4
Filing time
12 Dec 2025, 17:02:39 UTC
Previous filing
21 Nov 2025
Next filing
10 Mar 2026
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Muller Elizabeth Chief Executive Officer 2831 GARBER STREET, BERKELEY /s/ Jon Gordon, as Attorney-in-Fact for Elizabeth Muller 12 Dec 2025 0002081850

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction Restricted Stock Units Award $0 +549,451 $0.000000 549,451 09 Dec 2025 Direct F1

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction Stock Option (right to buy) Award $0 +183,150 +23% $0.000000 994,849 09 Dec 2025 shares of Common Stock 183,150 $2.73 Direct F2
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 Each restricted stock unit represents the contingent right to receive one share of the Issuer's common stock upon vesting. The units vest over four years, with 25% of the award vesting on the first anniversary of the December 9, 2025 grant date and the remaining 75% vesting in equal monthly installments thereafter, subject to the Reporting Person's continued service through each vesting date. Restricted stock units do not have an expiration date.
F2 The stock options vest over four years, with 25% of the award vesting on the first anniversary of the December 9, 2025 grant date and the remaining 75% vesting in equal monthly installments thereafter, subject to the Reporting Person's continued service through each vesting date.

Remarks:

Chief Executive Officer (Section 16 Officer). The equity awards reported herein were approved by the Issuer's Compensation Committee pursuant to Rule 16b-3. Power of Attorney authorizing the signer to execute and file this Form 4 on behalf of the Reporting Person is filed as Exhibit 24.