Filer Snapshot

DEEP FISSION, INC. SEC EDGAR Filings

SEC filings, ownership reports, and insider transactions for CIK 0001918102.

Entity Type

Company

Total Filings

93

Latest Filing

22 Apr 2026

Industry

Electric Services

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Source: SEC filing 8-K

8-K filed on 22 Apr 2026 for CIK 0001918102.

View Source Filing
Industry
Electric Services (Office Of Energy & Transportation)
Business address
2831 Garber Street, Berkeley, CA, 94705
State of incorporation
DE
Fiscal year end
31 December
Former names
Surfside Acquisition Inc. (to 08 Sep 2025)

Quick Takeaways

  • DEEP FISSION, INC. is an SEC filer tracked under CIK 0001918102.
  • 93 filings are listed on this profile.
  • Common form coverage includes 8-K, S-1/A, POS AM and more.

What Changed

  • Latest filing: 8-K filed on 22 Apr 2026.
  • Report period: 22 Apr 2026.

Why This Matters

  • You can quote filing dates and form types directly from the SEC record on this page.
  • Use this profile before deeper ownership or insider analysis to confirm filing history context.

Source Evidence

Source: SEC filing 8-K

8-K filed on 22 Apr 2026 for CIK 0001918102.

View Source Filing

Return Loop

Why revisit this filer page

A newly filed 8-K can change the filing history, ownership context, or next research path for DEEP FISSION, INC..

Latest source-backed update
8-K filed 22 Apr 2026
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  • Latest filing on record: 8-K filed 22 Apr 2026.
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Filer freshness comes from SEC EDGAR submission history and related source-backed ownership or portfolio filings when available.

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Latest update

What changed recently for DEEP FISSION, INC.

New fact period available

Latest financial period: Q4 2025. Open the source-backed page to inspect the fresh filing or facts context.

Update date

21 Apr 2026

Page type

Company facts

Latest period

Q4 2025

SEC-backed company facts were refreshed from filings filed on 21 Apr 2026.

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Benchmark Context

Benchmark context for this company

DEEP FISSION, INC. has a source-backed company facts view where you can compare the latest reported metrics with its own recent history and with peer rankings for the same metric.

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Why this is notable

Latest financial period: Q4 2025. That gives you a fresh baseline before you compare this company with peers.

  • Latest company facts filing date: 21 Apr 2026.
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Filer Overview

DEEP FISSION, INC. has filed 93 SEC EDGAR filings since 21 Mar 2022. Common forms include 8-K, S-1/A, POS AM, 10-K and more.

Electric Services Insider transactions Latest 13F filings

Latest Filings

Recent SEC filings for DEEP FISSION, INC. with direct links to document and filing folders.

Form type Document Filing Description Filing date Reporting date File number(s)
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K FORM 8-K 22 Apr 2026 22 Apr 2026 000-56407
S-1/A Open S-1/A document | Open XBRL data View SEC filing for S-1/A S-1/A 21 Apr 2026 333-293510
POS AM Open POS AM document | Open XBRL data View SEC filing for POS AM POS AM 21 Apr 2026 333-290438
10-K Open 10-K document | Open XBRL data View SEC filing for 10-K 10-K 15 Apr 2026 31 Dec 2025 000-56407
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K FORM 8-K 09 Apr 2026 09 Apr 2026 000-56407
NT 10-K Open NT 10-K document View SEC filing for NT 10-K NT 10-K 31 Mar 2026 31 Dec 2025 000-56407
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 10 Mar 2026 09 Mar 2026
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 10 Mar 2026 09 Mar 2026
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 10 Mar 2026 09 Mar 2026
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 10 Mar 2026 09 Mar 2026
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 10 Mar 2026 09 Mar 2026
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 10 Mar 2026 09 Mar 2026
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 10 Mar 2026 09 Mar 2026
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 10 Mar 2026 09 Mar 2026
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 10 Mar 2026 09 Mar 2026
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 10 Mar 2026 09 Mar 2026
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K FORM 8-K 05 Mar 2026 27 Feb 2026 000-56407
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K FORM 8-K 25 Feb 2026 18 Feb 2026 000-56407
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 24 Feb 2026 18 Feb 2026
4 Open 4 document View SEC filing for 4 23 Feb 2026 18 Feb 2026
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 23 Feb 2026 18 Feb 2026
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 23 Feb 2026 19 Feb 2026
3 Open 3 document View SEC filing for 3 OWNERSHIP DOCUMENT 23 Feb 2026 19 Feb 2026
D Open D document View SEC filing for D 18 Feb 2026 021-573851
S-1 Open S-1 document | Open XBRL data View SEC filing for S-1 S-1 17 Feb 2026 333-293510
424B3 Open 424B3 document View SEC filing for 424B3 424B3 10 Feb 2026 333-290438
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K FORM 8-K 10 Feb 2026 05 Feb 2026 000-56407
424B5 Open 424B5 document View SEC filing for 424B5 424B5 06 Feb 2026 333-290438
EFFECT Open EFFECT document View SEC filing for EFFECT 05 Feb 2026 333-290438
S-1/A Open S-1/A document | Open XBRL data View SEC filing for S-1/A S-1/A 27 Jan 2026 333-290438
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 07 Jan 2026 07 Nov 2025
3 Open 3 document View SEC filing for 3 OWNERSHIP DOCUMENT 07 Jan 2026 07 Nov 2025
S-1/A Open S-1/A document | Open XBRL data View SEC filing for S-1/A S-1/A 30 Dec 2025 333-290438
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 23 Dec 2025 19 Dec 2025
3 Open 3 document View SEC filing for 3 OWNERSHIP DOCUMENT 23 Dec 2025 19 Dec 2025
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K FORM 8-K 22 Dec 2025 19 Dec 2025 000-56407
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 22 Dec 2025 12 Nov 2025
3 Open 3 document View SEC filing for 3 OWNERSHIP DOCUMENT 22 Dec 2025 07 Nov 2025
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 12 Dec 2025 09 Dec 2025
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K FORM 8-K 11 Dec 2025 09 Dec 2025 000-56407
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K FORM 8-K 04 Dec 2025 04 Dec 2025 000-56407
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 04 Dec 2025 07 Nov 2025
3 Open 3 document View SEC filing for 3 OWNERSHIP DOCUMENT 04 Dec 2025 07 Nov 2025
S-1/A Open S-1/A document | Open XBRL data View SEC filing for S-1/A S-1/A 01 Dec 2025 333-290438
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K FORM 8-K 21 Nov 2025 17 Nov 2025 000-56407
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 17 Nov 2025 12 Nov 2025
3 Open 3 document View SEC filing for 3 OWNERSHIP DOCUMENT 17 Nov 2025 07 Nov 2025
4 Open 4 document View SEC filing for 4 OWNERSHIP DOCUMENT 14 Nov 2025 12 Nov 2025
3 Open 3 document View SEC filing for 3 OWNERSHIP DOCUMENT 14 Nov 2025 07 Nov 2025
10-Q Open 10-Q document | Open XBRL data View SEC filing for 10-Q 10-Q 14 Nov 2025 30 Sep 2025 000-56407
SCHEDULE 13G/A Open SCHEDULE 13G/A document View SEC filing for SCHEDULE 13G/A 14 Nov 2025 005-93944
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K CURRENT REPORT 12 Nov 2025 07 Nov 2025 000-56407
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K FORM 8-K 07 Nov 2025 06 Nov 2025 000-56407
SCHEDULE 13G Open SCHEDULE 13G document View SEC filing for SCHEDULE 13G 03 Nov 2025 005-93944
S-1/A Open S-1/A document | Open XBRL data View SEC filing for S-1/A AMENDMENT NO 1. TO FORM S-1 24 Sep 2025 333-290438
D Open D document View SEC filing for D 24 Sep 2025 021-558495
SCHEDULE 13D Open SCHEDULE 13D document View SEC filing for SCHEDULE 13D 23 Sep 2025 005-93944
SCHEDULE 13D Open SCHEDULE 13D document View SEC filing for SCHEDULE 13D 23 Sep 2025 005-93944
D Open D document View SEC filing for D 23 Sep 2025 021-558291
S-1 Open S-1 document | Open XBRL data View SEC filing for S-1 REGISTRATION STATEMENT 22 Sep 2025 333-290438
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K CURRENT REPORT 11 Sep 2025 05 Sep 2025 000-56407
4 Open 4 document View SEC filing for 4 09 Sep 2025 05 Sep 2025
3 Open 3 document View SEC filing for 3 09 Sep 2025 05 Sep 2025
4 Open 4 document View SEC filing for 4 09 Sep 2025 05 Sep 2025
3 Open 3 document View SEC filing for 3 09 Sep 2025 05 Sep 2025
4 Open 4 document View SEC filing for 4 09 Sep 2025 05 Sep 2025
3 Open 3 document View SEC filing for 3 09 Sep 2025 05 Sep 2025
4 Open 4 document View SEC filing for 4 08 Sep 2025 05 Sep 2025
4 Open 4 document View SEC filing for 4 28 Aug 2025 26 Aug 2025
4 Open 4 document View SEC filing for 4 28 Aug 2025 26 Aug 2025
SC 14F1 Open SC 14F1 document View SEC filing for SC 14F1 SCHEDULE 14F-1 25 Aug 2025 005-93944
10-Q Open 10-Q document | Open XBRL data View SEC filing for 10-Q QUARTERLY REPORT 12 Aug 2025 30 Jun 2025 000-56407
10-Q Open 10-Q document | Open XBRL data View SEC filing for 10-Q QUARTERLY REPORT 14 May 2025 31 Mar 2025 000-56407
10-K Open 10-K document | Open XBRL data View SEC filing for 10-K ANNUAL REPORT 28 Mar 2025 31 Dec 2024 000-56407
10-Q Open 10-Q document | Open XBRL data View SEC filing for 10-Q QUARTERLY REPORT 06 Nov 2024 30 Sep 2024 000-56407
10-Q Open 10-Q document | Open XBRL data View SEC filing for 10-Q QUARTERLY REPORT 13 Aug 2024 30 Jun 2024 000-56407
10-Q Open 10-Q document | Open XBRL data View SEC filing for 10-Q QUARTERLY REPORT 14 May 2024 31 Mar 2024 000-56407
10-K Open 10-K document | Open XBRL data View SEC filing for 10-K ANNUAL REPORT 01 Apr 2024 31 Dec 2023 000-56407
10-Q Open 10-Q document | Open XBRL data View SEC filing for 10-Q QUARTERLY REPORT 13 Nov 2023 30 Sep 2023 000-56407
10-Q Open 10-Q document | Open XBRL data View SEC filing for 10-Q QUARTERLY REPORT 10 Aug 2023 30 Jun 2023 000-56407
10-Q Open 10-Q document | Open XBRL data View SEC filing for 10-Q QUARTERLY REPORT 15 May 2023 31 Mar 2023 000-56407
10-K Open 10-K document | Open XBRL data View SEC filing for 10-K ANNUAL REPORT 31 Mar 2023 31 Dec 2022 000-56407
SC 13G Open SC 13G document View SEC filing for SC 13G SCHEDULE 13G 13 Feb 2023 005-93944
SC 13G Open SC 13G document View SEC filing for SC 13G SCHEDULE 13G 10 Feb 2023 005-93944
10-Q Open 10-Q document | Open XBRL data View SEC filing for 10-Q QUARTERLY REPORT 14 Nov 2022 30 Sep 2022 000-56407
10-Q Open 10-Q document | Open XBRL data View SEC filing for 10-Q QUARTERLY REPORT 15 Aug 2022 30 Jun 2022 000-56407
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K CURRENT REPORT 28 Jul 2022 22 Jul 2022 000-56407
8-K Open 8-K document | Open XBRL data View SEC filing for 8-K CURRENT REPORT 19 Jul 2022 13 Jul 2022 000-56407
10-Q Open 10-Q document | Open XBRL data View SEC filing for 10-Q QUARTERLY REPORT 16 May 2022 31 Mar 2022 000-56407
3 Open 3 document View SEC filing for 3 20 Apr 2022 20 Apr 2022
3 Open 3 document View SEC filing for 3 20 Apr 2022 20 Apr 2022
SEC STAFF ACTION Open SEC STAFF ACTION document View SEC filing for SEC STAFF ACTION 20 Apr 2022
10-12G Open 10-12G document View SEC filing for 10-12G GENERAL FORM FOR REGISTRATION OF SECURITIES 21 Mar 2022 000-56407

About this filer

DEEP FISSION, INC. files with the SEC under CIK 0001918102. This page aggregates EDGAR filings and related ownership activity.

Industry: Electric Services.

FAQ

What is a CIK?
A Central Index Key (CIK) is a unique identifier assigned by the SEC to each filer.
Why are some filings missing?
New filings appear as the SEC updates EDGAR, and older records can vary by availability.
How often is this page updated?
Updates follow new EDGAR submissions and periodic data refreshes.