IPO registrations (S-1, F-1) · Registrants
DEEP FISSION, INC.
- SEC CIK
- 1918102 · filings on EDGAR ↗
- Former names
- Surfside Acquisition Inc. (2022–2025)
- Registration
- Form S-1, first filed 2025-09-22, last 2026-06-10; 3 initial registrations, 6 amendments
- Outcome
- Final prospectus filed 2026-06-18; declared effective 2026-02-05
- Industry (SIC)
- Electric Services 4911
- Incorporated in
- DE
- Business address
- 2831 GARBER STREET, Berkeley, CA 94705
- EIN
- 87-4265302
- Ticker
- FISN (Nasdaq)
- EDGAR entity type
- operating
- Insiders and CEO pay
- DEEP FISSION, INC. on the corporate pages
Offering terms
- Proposed price range
- $16.00–$18.00 per share (S-1/A filed 2026-06-10)
- Final price
- $16.00 per share, within the range (424B4 filed 2026-06-18)
- Shares sold
- 2,500,000
- Gross proceeds
- $40,000,000 before underwriting discounts and any over-allotment option
- Listing
- Nasdaq under the symbol FISN
- Lead underwriters
- The Benchmark Company
- Syndicate
- Maxim Group
Read from the cover pages of the filings listed under “Prospectus pages read” below; check the document for anything that matters.
On this site
- Business registration: Deep Fission Inc Fuzzy (name and state)
- Business registration: Deep Fission Inc. Fuzzy (name and state)
- Business registration: DEEP FISSION, INC. Fuzzy (name and state)
- Federal award recipient: DEEP FISSION, INC. Fuzzy (name and state)
- Form D issuer: DEEP FISSION, INC. EXACT (CIK (EXACT))
- Lobbying client: DEEP FISSION INC. Fuzzy (name and state)
- Lobbying client: DEEP FISSION, INC. Fuzzy (name and state)
- Lobbying registrant: DEEP FISSION INC. Fuzzy (name and state)
- SEC filer: DEEP FISSION, INC. EXACT (CIK (EXACT))
Filings 14
| Filed | Form | What it is | Name as filed | EDGAR |
|---|---|---|---|---|
| 2025-09-22 | S-1 | S-1 (registration) | DEEP FISSION, INC. | 0001213900-25-089735 ↗ |
| 2025-09-24 | S-1/A | S-1/A (amendment) | DEEP FISSION, INC. | 0001213900-25-091209 ↗ |
| 2025-12-01 | S-1/A | S-1/A (amendment) | DEEP FISSION, INC. | 0001104659-25-117373 ↗ |
| 2025-12-30 | S-1/A | S-1/A (amendment) | DEEP FISSION, INC. | 0001104659-25-125146 ↗ |
| 2026-01-27 | S-1/A | S-1/A (amendment) | DEEP FISSION, INC. | 0001104659-26-006743 ↗ |
| 2026-02-05 | EFFECT | EFFECT (declared effective) | DEEP FISSION, INC. | 9999999995-26-000450 ↗ |
| 2026-02-17 | S-1 | S-1 (registration) | DEEP FISSION, INC. | 0001104659-26-016226 ↗ |
| 2026-04-21 | S-1/A | S-1/A (amendment) | DEEP FISSION, INC. | 0001104659-26-045974 ↗ |
| 2026-05-01 | EFFECT | EFFECT (declared effective) | DEEP FISSION, INC. | 9999999995-26-001430 ↗ |
| 2026-05-01 | EFFECT | EFFECT (declared effective) | DEEP FISSION, INC. | 9999999995-26-001434 ↗ |
| 2026-05-20 | S-1 | S-1 (registration) | DEEP FISSION, INC. | 0001104659-26-064074 ↗ |
| 2026-06-10 | S-1/A | S-1/A (amendment) | DEEP FISSION, INC. | 0001104659-26-072286 ↗ |
| 2026-06-17 | EFFECT | EFFECT (declared effective) | DEEP FISSION, INC. | 9999999995-26-002042 ↗ |
| 2026-06-18 | 424B4 | 424B4 (final prospectus) | DEEP FISSION, INC. | 0001104659-26-075763 ↗ |
Prospectus pages read 2
| Filed | Form | Read as | Range | Price | Shares | Proceeds | Listing | Underwriters | What was found | Document |
|---|---|---|---|---|---|---|---|---|---|---|
| 2026-06-10 | S-1/A | registration statement | $16.00–$18.00 | 2,500,000 | - | Nasdaq FISN | 3 | primary document; range, shares headline, cover names 3 | document ↗ | |
| 2026-06-18 | 424B4 | final prospectus | $16.00 | 2,500,000 | $40,000,000 | Nasdaq FISN | 2 | primary document; price sentence, shares headline, proceeds table, cover names 2 | document ↗ |
Officers, directors and large holders Forms 3, 4 and 5
| Insider | Role | Title | Filings | Years | On this site |
|---|---|---|---|---|---|
| Jacobs Ian Seth | Director,Officer | President, CEO, CFO, Secretary | 2 | 2022–2025 | |
| Tompkins Mark N. | Director,TenPercentOwner; Other | 3 | 2022–2025 | ||
| Muller Elizabeth | Director,Officer; Officer | Chief Executive Officer; President and Chief Executive | 4 | 2025–2026 | |
| Muller Richard | Director,Officer; Officer | Chief Technology Officer | 3 | 2025–2026 | |
| Schmitz William Mark | Officer | Chief Financial Officer | 4 | 2025–2026 | |
| Goldman Tepper Leslie | Director | 5 | 2025–2026 | ||
| Angell Jonathon | Director | 4 | 2025–2026 | ||
| Gordon Jonathan H | Officer | General Counsel; See Remarks | 4 | 2025–2026 | |
| GLANVILLE THOMAS S | Director | 4 | 2025–2026 | ||
| JANOVER BLAKE | Director | 4 | 2025–2026 | ||
| Brasel Michael Allen | Officer | Chief Operating Officer; See Remarks | 4 | 2026 | |
| Peres Mark Wayne | Officer | Chief Nuclear Officer | 3 | 2026 |
Everyone who filed an insider report for this company, from the SEC’s Insider Transactions Data Sets (2006 on). Person pages are matched by name and state only.
Private offerings before or after (Form D)
| First filed | Issuer | Industry | Offering | Sold | Investors | Filings |
|---|---|---|---|---|---|---|
| 2026-02-18 | DEEP FISSION, INC. | Other Energy | $79,999,995 | $79,999,995 | 223 | 1 |
| 2025-09-24 | DEEP FISSION, INC. | Other Energy | $120,000,000 | $0 | 83 | 1 |
| 2025-09-23 | DEEP FISSION, INC. | Other Energy | $31,759,998 | $30,000,000 | 100 | 1 |
Data: SEC EDGAR. The quarterly full index (every S-1, S-1/A, F-1 and F-1/A since 1993, with the pricing prospectus, notice of effectiveness and withdrawal request of each registrant) and the company submissions data (SIC, state of incorporation, address, EIN, tickers, former names). Company details are what EDGAR holds today, not at the time of the filing.
Also on this site Fuzzy
| Record | Name as filed | Where | Dataset | Matched by |
|---|---|---|---|---|
| Business registration | Deep Fission Inc | CA | State business registries | name and state |
| Business registration | Deep Fission Inc. | CA | State business registries | name and state |
| Business registration | DEEP FISSION, INC. | CA | State business registries | name and state |
| Federal award recipient | DEEP FISSION, INC. | CA | Federal spending (USAspending) | name and state |
| Form D issuer | DEEP FISSION, INC. | CA | Form D private offerings | CIK (EXACT) |
| Lobbying client | DEEP FISSION INC. | CA | Federal lobbying (LDA) | name and state |
| Lobbying client | DEEP FISSION, INC. | CA | Federal lobbying (LDA) | name and state |
| Lobbying registrant | DEEP FISSION INC. | CA | Federal lobbying (LDA) | name and state |
| Nonprofit | BERKELEY EARTH INC | CA | Nonprofits (IRS Form 990) | same street address and ZIP code, 2831 GARBER ST 94705 (FUZZY: a shared address, not proof of a shared organization) |
| Patent assignee | Deep Fission, Inc. | CA | Patents (USPTO) | name and state |
| SEC filer | DEEP FISSION, INC. | SEC filers (EDGAR) | CIK (EXACT) | |
| Trademark owner | Deep Fission, Inc. | CA | Trademarks (USPTO) | name and state |
Matched by an identifier (EIN, CIK, CRD), by name and state or city, or by street address; a shared name or address is not proof of the same person or organization. Every link says how it was made; how the cross-referencing works.