Elizabeth Muller - 11 Nov 2026 Form 4 Insider Report for DEEP FISSION, INC. (FISN)

Reporting relationship: CEO, President, Director, 10%+ Owner
Issuer ticker: FISN
Reported as of: 11 Nov 2026
Net transaction value: +$21,612
SEC form: 4
Accepted by SEC: 13 Nov 2026, 18:00:11 UTC
Prior SEC filing: 08 Oct 2026
Source filing: View source filing
Reporting owner signature: /s/ Elizabeth Muller

Filing notes and source

Key filing fact

Elizabeth Muller filed Form 4 for DEEP FISSION, INC. (FISN) on 13 Nov 2026.

Key facts

This page summarizes Elizabeth Muller's Form 4 filing for DEEP FISSION, INC. (FISN).
1 reported transaction and 0 derivative rows are listed below.
Accepted by SEC: 13 Nov 2026, 18:00.

Change

Previous filing in this sequence was filed on 08 Oct 2026.
Current net transaction value: +$21,612.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0002081850 Primary reporting owner

Muller Elizabeth

Relationship: CEO, President, Director, 10%+ Owner
Address: 2001 ADDISON STREET, SUITE 300, BERKELEY
Signature: /s/ Elizabeth Muller
Signature date: 13 Nov 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

FISN transaction

Common Stock

Purchase

Transaction value: $21,612
Shares: +10,000
Change %
Price: $2.16
Shares after: 10,000
Date: 11 Nov 2026
Ownership: Direct
Footnotes: F1

FISN holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 5,057,852
Date: 11 Nov 2026
Ownership: By Muller Family Trust
Footnotes: F2

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

The price reported in Column 4 is a weighted average price. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares purchased at each price within the range set forth in this footnote (1) to this Form 4.

Footnote F2

In her capacity as trustee of the Muller Family Trust (the "Muller Trust"), Ms. Muller controls the right to vote and dispose of the shares held by the Muller Trust and accordingly, may be deemed to beneficially own the shares held by the Muller Trust. Ms. Muller expressly disclaims beneficial ownership of all securities held by the Muller Trust except to the extent of her pecuniary interest therein.