Deep Fission, Inc. SEC filings FISN
Deep Fission, Inc. has 123 filings in SEC EDGAR's recent list, going back to Mar 21, 2022. Its latest annual report, Form 10-K, was filed on Apr 15, 2026 for the period ended Dec 31, 2025. The latest quarterly report (Form 10-Q) was filed on Nov 4, 2026, covering the quarter ended Sep 30, 2026. The most recent current report (Form 8-K) was filed on Oct 20, 2026 (regulation fd disclosure). The company's fiscal year ends on December 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| 4 | Insider transaction | Jul 27, 2026 | Jul 23, 2026 |
| 4 | Insider transaction | Jul 27, 2026 | Jul 23, 2026 |
| 4 | Insider transaction | Jul 27, 2026 | Jul 23, 2026 |
| 4 | Insider transaction | Jul 27, 2026 | Jul 23, 2026 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | May 15, 2026 | — |
| 3/A | Ownership document | Apr 29, 2026 | Apr 28, 2026 |
| 4 | Insider transaction | Mar 10, 2026 | Mar 9, 2026 |
| 4 | Insider transaction | Mar 10, 2026 | Mar 9, 2026 |
| 4 | Insider transaction | Mar 10, 2026 | Mar 9, 2026 |
| 4 | Insider transaction | Mar 10, 2026 | Mar 9, 2026 |
| 4 | Insider transaction | Mar 10, 2026 | Mar 9, 2026 |
| 4 | Insider transaction | Mar 10, 2026 | Mar 9, 2026 |
| 4 | Insider transaction | Mar 10, 2026 | Mar 9, 2026 |
| 4 | Insider transaction | Mar 10, 2026 | Mar 9, 2026 |
| 4 | Insider transaction | Mar 10, 2026 | Mar 9, 2026 |
| 4 | Insider transaction | Mar 10, 2026 | Mar 9, 2026 |
| 4 | Insider transaction | Feb 24, 2026 | Feb 18, 2026 |
| 4 | Insider transaction | Feb 23, 2026 | Feb 18, 2026 |
| 4 | Insider transaction | Feb 23, 2026 | Feb 18, 2026 |
| 4 | Insider transaction | Feb 23, 2026 | Feb 19, 2026 |
| 3 | Initial insider ownership | Feb 23, 2026 | Feb 19, 2026 |
| 4 | Insider transaction | Jan 7, 2026 | Nov 7, 2025 |
| 3 | Initial insider ownership | Jan 7, 2026 | Nov 7, 2025 |
| 4 | Insider transaction | Dec 23, 2025 | Dec 19, 2025 |
| 3 | Initial insider ownership | Dec 23, 2025 | Dec 19, 2025 |
| 4 | Insider transaction | Dec 22, 2025 | Nov 12, 2025 |
| 3 | Initial insider ownership | Dec 22, 2025 | Nov 7, 2025 |
| 4 | Insider transaction | Dec 12, 2025 | Dec 9, 2025 |
| 4 | Insider transaction | Dec 4, 2025 | Nov 7, 2025 |
| 3 | Initial insider ownership | Dec 4, 2025 | Nov 7, 2025 |
| 4 | Insider transaction | Nov 17, 2025 | Nov 12, 2025 |
| 3 | Initial insider ownership | Nov 17, 2025 | Nov 7, 2025 |
| 4 | Insider transaction | Nov 14, 2025 | Nov 12, 2025 |
| 3 | Initial insider ownership | Nov 14, 2025 | Nov 7, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Nov 14, 2025 | — |
| SCHEDULE 13G | Ownership over 5% (passive) | Nov 3, 2025 | — |
| SCHEDULE 13D | Ownership over 5% (active) | Sep 23, 2025 | — |
| SCHEDULE 13D | Ownership over 5% (active) | Sep 23, 2025 | — |
| 4 | Insider transaction | Sep 9, 2025 | Sep 5, 2025 |
| 3 | Initial insider ownership | Sep 9, 2025 | Sep 5, 2025 |
| 4 | Insider transaction | Sep 9, 2025 | Sep 5, 2025 |
| 3 | Initial insider ownership | Sep 9, 2025 | Sep 5, 2025 |
| 4 | Insider transaction | Sep 9, 2025 | Sep 5, 2025 |
| 3 | Initial insider ownership | Sep 9, 2025 | Sep 5, 2025 |
| 4 | Insider transaction | Sep 8, 2025 | Sep 5, 2025 |
| 4 | Insider transaction | Aug 28, 2025 | Aug 26, 2025 |
| 4 | Insider transaction | Aug 28, 2025 | Aug 26, 2025 |
| SC 13G | Ownership over 5% (passive) | Feb 13, 2023 | — |
| SC 13G | Ownership over 5% (passive) | Feb 10, 2023 | — |
| 3 | Initial insider ownership | Apr 20, 2022 | Apr 20, 2022 |
| 3 | Initial insider ownership | Apr 20, 2022 | Apr 20, 2022 |
Showing 51 filings. Main filings leave out insider and ownership forms such as Form 4; choose a type above to see them. Each form opens on SEC.gov. Older filings are on SEC EDGAR.
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Company profile
- Industry
- Electric Services (SIC 4911)
- Listed as
- FISN (Nasdaq)
- Fiscal year ends
- December 31
- Incorporated in
- DE
- Headquarters
- Berkeley, CA
- SEC filer status
- Non-accelerated filer, Smaller reporting company, Emerging growth company
- SEC CIK
- 1918102
- Former names
- Surfside Acquisition Inc. (until Sep 8, 2025)
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Source: SEC EDGAR filings. This is company-reported data, not investment advice.