Deep Fission, Inc.
FISN- Exchange
- Nasdaq
- Industry
- Electric Services
- SEC CIK
- 0001918102
No open-market purchases or sales by Deep Fission, Inc. insiders were filed in the last 90 days; 21 institutions reported holding it in 13F filings for Q2 2026, worth $25.2M in total; no superinvestor holds it.
Open-market trades, last 90 days
Open-market purchases (P) and sales (S) by Deep Fission, Inc. insiders, counted by Form 4 filing. Trades with a flagged price and duplicate filings are left out.
- Open-market buys
- 0 filings
- Open-market sells
- 0 filings
- Insiders trading
- 0
- Net value
- $0
- Purchases minus sales
Insider roster
Directors, officers and 10% owners who have filed a Form 4 for Deep Fission, Inc., current and former, most recent filer first. Last reported holding is the position after the last non-derivative trade in their latest filing.
| Name | Title | Last reported holding | Last filing | Filings, past year |
|---|---|---|---|---|
| Glanville Thomas S | Director | – | Jul 27, 2026 | 3 |
| Janover Blake | Director | – | Jul 27, 2026 | 3 |
| Goldman Tepper Leslie | Director | – | Jul 27, 2026 | 3 |
| Angell Jonathon | Director | – | Jul 27, 2026 | 3 |
| Schmitz William Mark | Chief Financial Officer | 103,928 | Mar 10, 2026 | 2 |
| Muller Elizabeth | Chief Executive Officer | 549,451 | Mar 10, 2026 | 2 |
| Muller Richard | Chief Technology Officer | 5,196,426 | Mar 10, 2026 | 1 |
| Gordon Jonathan H | General Counsel | – | Mar 10, 2026 | 3 |
| Brasel Michael Allen | Chief Operating Officer | – | Mar 10, 2026 | 3 |
| Peres Mark Wayne | Chief Nuclear Officer | – | Mar 10, 2026 | 2 |
| Tompkins Mark N. | Other: See Remarks | 1,891,667 | Sep 8, 2025 | 0 |
| Jacobs Ian Seth | President, CEO, CFO, Secretary | 275,000 | Aug 28, 2025 | 0 |
Insider trades
Each row adds up one type of transaction in one Form 4 filing. Only open-market purchases (P) and sales (S) are shown by default; use the filters to see grants, option exercises and other codes.
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Aug 28, 2025 (view filing) | Aug 26 | 2 days | Tompkins Mark N.Director, 10% Owner | SSale | −25.0K | $0.00 | $0 | −0.5%4.72M after | |
| Aug 28, 2025 (view filing) | Aug 26 | 2 days | Jacobs Ian SethPresident, CEO, CFO, Secretary | PPurchase | +25.0K | $0.00 | $0 | +10.0%275.0K after |