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 |
|---|---|---|---|
| S-3 | Shelf registration | Nov 4, 2026 | — |
| 10-Q | Quarterly report | Nov 4, 2026 | Sep 30, 2026 |
| 8-K |
Current report
Regulation FD disclosure
|
Oct 20, 2026 | Oct 20, 2026 |
| 8-K |
Current report
Regulation FD disclosure
|
Sep 21, 2026 | Sep 21, 2026 |
| 10-Q | Quarterly report | Aug 3, 2026 | Jun 30, 2026 |
| 8-K |
Current report
Other events
|
Jul 29, 2026 | Jul 29, 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 |
| 4 | Insider transaction | Jul 27, 2026 | Jul 23, 2026 |
| S-8 | Employee stock plan registration | Jul 20, 2026 | — |
| 8-K |
Current report
Officer or director change, Shareholder vote results
|
Jul 17, 2026 | Jul 17, 2026 |
| 8-K |
Current report
Other events
|
Jun 22, 2026 | Jun 22, 2026 |
| 424B4 | Prospectus | Jun 18, 2026 | — |
| EFFECT | Filing | Jun 17, 2026 | — |
| DEF 14A | Proxy statement | Jun 17, 2026 | Jul 17, 2026 |
| CERT | Filing | Jun 17, 2026 | — |
| S-1/A | Amended registration statement | Jun 10, 2026 | — |
| 8-A12B | Filing | May 28, 2026 | — |
| S-1 | Registration statement | May 20, 2026 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | May 15, 2026 | — |
| 10-Q | Quarterly report | May 8, 2026 | Mar 31, 2026 |
| EFFECT | Filing | May 1, 2026 | — |
| EFFECT | Filing | May 1, 2026 | — |
| 424B3 | Prospectus | May 1, 2026 | — |
| 424B3 | Prospectus | May 1, 2026 | — |
| CORRESP | Letter to the SEC | Apr 29, 2026 | — |
| 3/A | Ownership document | Apr 29, 2026 | Apr 28, 2026 |
| 8-K |
Current report
Regulation FD disclosure
|
Apr 22, 2026 | Apr 22, 2026 |
| DRS | Filing | Apr 22, 2026 | — |
| S-1/A | Amended registration statement | Apr 21, 2026 | — |
| POS AM | Filing | Apr 21, 2026 | — |
| 10-K | Annual report | Apr 15, 2026 | Dec 31, 2025 |
| 8-K |
Current report
Restatement
|
Apr 9, 2026 | Apr 9, 2026 |
| NT 10-K | Filing | Mar 31, 2026 | Dec 31, 2025 |
| 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 |
| 8-K |
Current report
Auditor change
|
Mar 5, 2026 | Feb 27, 2026 |
| 8-K |
Current report
Officer or director change
|
Feb 25, 2026 | Feb 18, 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 |
| UPLOAD | Letter from the SEC | Feb 23, 2026 | — |
| D | Filing | Feb 18, 2026 | — |
| S-1 | Registration statement | Feb 17, 2026 | — |
| 424B3 | Prospectus | Feb 10, 2026 | — |
| 8-K |
Current report
Material agreement, Unregistered share sale, Regulation FD disclosure, Other events
|
Feb 10, 2026 | Feb 5, 2026 |
| 424B5 | Prospectus supplement | Feb 6, 2026 | — |
| EFFECT | Filing | Feb 5, 2026 | — |
| S-1/A | Amended registration statement | Jan 27, 2026 | — |
| 4 | Insider transaction | Jan 7, 2026 | Nov 7, 2025 |
| 3 | Initial insider ownership | Jan 7, 2026 | Nov 7, 2025 |
| S-1/A | Amended registration statement | Dec 30, 2025 | — |
| 4 | Insider transaction | Dec 23, 2025 | Dec 19, 2025 |
| 3 | Initial insider ownership | Dec 23, 2025 | Dec 19, 2025 |
| 8-K |
Current report
Officer or director change, Other events
|
Dec 22, 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 |
| 8-K |
Current report
Officer or director change
|
Dec 11, 2025 | Dec 9, 2025 |
| 8-K |
Current report
Regulation FD disclosure
|
Dec 4, 2025 | Dec 4, 2025 |
| 4 | Insider transaction | Dec 4, 2025 | Nov 7, 2025 |
| 3 | Initial insider ownership | Dec 4, 2025 | Nov 7, 2025 |
| S-1/A | Amended registration statement | Dec 1, 2025 | — |
| 8-K |
Current report
Material agreement
|
Nov 21, 2025 | Nov 17, 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 |
| 10-Q | Quarterly report | Nov 14, 2025 | Sep 30, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Nov 14, 2025 | — |
| 8-K |
Current report
Officer or director change
|
Nov 12, 2025 | Nov 7, 2025 |
| 8-K |
Current report
Regulation FD disclosure
|
Nov 7, 2025 | Nov 6, 2025 |
| SCHEDULE 13G | Ownership over 5% (passive) | Nov 3, 2025 | — |
| S-1/A | Amended registration statement | Sep 24, 2025 | — |
| D | Filing | Sep 24, 2025 | — |
| SCHEDULE 13D | Ownership over 5% (active) | Sep 23, 2025 | — |
| SCHEDULE 13D | Ownership over 5% (active) | Sep 23, 2025 | — |
| D | Filing | Sep 23, 2025 | — |
| S-1 | Registration statement | Sep 22, 2025 | — |
| 8-K |
Current report
Material agreement, Acquisition or sale of assets, Unregistered share sale, Change to shareholder rights, Auditor change, Change in control, Officer or director change, Bylaw or fiscal year change
|
Sep 11, 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 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 14F1 | Schedule 14f-1 | Aug 25, 2025 | — |
| 10-Q | Quarterly report | Aug 12, 2025 | Jun 30, 2025 |
| 10-Q | Quarterly report | May 14, 2025 | Mar 31, 2025 |
| 10-K | Annual report | Mar 28, 2025 | Dec 31, 2024 |
| 10-Q | Quarterly report | Nov 6, 2024 | Sep 30, 2024 |
| 10-Q | Quarterly report | Aug 13, 2024 | Jun 30, 2024 |
| 10-Q | Quarterly report | May 14, 2024 | Mar 31, 2024 |
| 10-K | Annual report | Apr 1, 2024 | Dec 31, 2023 |
| 10-Q | Quarterly report | Nov 13, 2023 | Sep 30, 2023 |
| 10-Q | Quarterly report | Aug 10, 2023 | Jun 30, 2023 |
| 10-Q | Quarterly report | May 15, 2023 | Mar 31, 2023 |
| 10-K | Annual report | Mar 31, 2023 | Dec 31, 2022 |
| SC 13G | Ownership over 5% (passive) | Feb 13, 2023 | — |
| SC 13G | Ownership over 5% (passive) | Feb 10, 2023 | — |
| 10-Q | Quarterly report | Nov 14, 2022 | Sep 30, 2022 |
| 10-Q | Quarterly report | Aug 15, 2022 | Jun 30, 2022 |
| 8-K |
Current report
Auditor change
|
Jul 28, 2022 | Jul 22, 2022 |
| 8-K |
Current report
Auditor change
|
Jul 19, 2022 | Jul 13, 2022 |
| 10-Q | Quarterly report | May 16, 2022 | Mar 31, 2022 |
| 3 | Initial insider ownership | Apr 20, 2022 | Apr 20, 2022 |
| 3 | Initial insider ownership | Apr 20, 2022 | Apr 20, 2022 |
| SEC STAFF ACTION | Filing | Apr 20, 2022 | — |
| 10-12G | General form for registration of securities | Mar 21, 2022 | — |
Showing 123 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.
New to this? Read What Are SEC Filings? 10-K, 10-Q, 8-K and Other Forms Explained.
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)
Other Electric Services companies
- Nextera Energy Inc NEE
- Southern Co SO
- Constellation Energy Corp CEG
- American Electric Power Co Inc AEP
- Dominion Energy, Inc D
- Entergy Corp /DE/ ETR
- Vistra Corp. VST
- Fortis Inc. FTS
Source: SEC EDGAR filings. This is company-reported data, not investment advice.