Insider Transactions Reported by 12 Insiders of DEEP FISSION, INC.

Location
Berkeley, CA

Quick Takeaways

  • DEEP FISSION, INC. has 12 insiders with reported activity on this page.
  • No net insider buy/sell flow is currently reported for the last year.
  • Recent transaction rows are available for direct filing-level review.

What Changed

  • No meaningful buy/sell imbalance is currently visible in the one-year window.
  • Activity will update as new Forms 3/4/5 are filed.

Why This Matters

  • This page gives a plain-language issuer insider context before you inspect transaction-level evidence.
  • Use the filing links below to verify timestamps, codes, and ownership impacts directly from SEC forms.

Source Evidence

Filed on Form 4

Issuer insider activity is sourced from SEC Forms 3, 4, and 5.

See Original Filing

Insider trading overview

Last 12 months

Insider buy and sell flow is broadly balanced over the last 12 months. No Buy or Sell transactions have been reported since 19 Apr 2025.

Buys

$0

Shares: 0

Insiders: 0

Sells

$0

Shares: 0

Insiders: 0

Net

$0

Shares: 0

Insiders: 0

Window (months) Buy shares Sell shares Buy $ Sell $ Net $
0-3 0 0 $0 $0 $0
3-6 0 0 $0 $0 $0
6-9 0 0 $0 $0 $0
9-12 0 0 $0 $0 $0

DEEP FISSION, INC. executives and other stock owners filed with the SEC include:

Name Relationship Holdings Value Past Year Net Change Change % Valuation Report Date
Michael Allen Brasel Chief Operating Officer Mixed 09 Mar 2026
Elizabeth Muller Chief Executive Officer Mixed 09 Mar 2026
Leslie Goldman Tepper Director Mixed 09 Mar 2026
Jonathon Angell Director Mixed 09 Mar 2026
Thomas S. Glanville Director Mixed 09 Mar 2026
Blake Janover Director Mixed 09 Mar 2026
Richard Muller Chief Technology Officer Mixed 09 Mar 2026
Mark Wayne Peres Chief Nuclear Officer Mixed 09 Mar 2026
Jonathan H. Gordon General Counsel Mixed 09 Mar 2026
William A. Schmitz Chief Financial Officer Mixed 09 Mar 2026
Mark N. Tompkins The reporting person is a former director and former 10% owner in the Issuer. Mixed 05 Sep 2025
Ian Seth Jacobs President, CEO, CFO, Secretary, Director Mixed 26 Aug 2025

Top shareholders of DEEP FISSION, INC. (13F + 13D/G + 3/4/5)

Grouped by holder across the latest SEC ownership disclosures. Ownership % is shown only when it is directly reported or safely comparable across share classes.

Methodology: rows are grouped by holder and ranked by the holder's primary source value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Holder Source Role / Reporting Ownership % Shares Holdings Value 12M Net Δ As of Details
Elizabeth Muller
3/4/5 13D/G
Chief Executive Officer · Muller Elizabeth
21%
from 13D/G
15,948,881
mixed-class rows
 — — 09 Mar 2026
3/4/5 13D/G
Richard Muller
3/4/5 13D/G
Chief Technology Officer · Muller Richard
11%
from 13D/G
6,068,789
mixed-class rows
 — — 09 Mar 2026
3/4/5 13D/G
Mark N. Tompkins
13D/G 3/4/5
The reporting person is a former director and former 10% owner in the Issuer.
5.8%
2,958,333
 — $0 30 Sep 2025
13D/G 3/4/5
EE Holdings Ltd
13D/G
EE HOLDINGS LIMITED
5.5%
2,866,667
 — $0 30 Sep 2025
13D/G
Michael Allen Brasel
3/4/5
Chief Operating Officer —
class O/S missing
530,000
 — — 09 Mar 2026
3/4/5
Jonathon Angell
3/4/5
Director —
mixed-class rows
427,851
mixed-class rows
 — — 09 Mar 2026
3/4/5
Mark Wayne Peres
3/4/5
Chief Nuclear Officer —
mixed-class rows
374,607
mixed-class rows
 — — 09 Mar 2026
3/4/5
Jonathan H. Gordon
3/4/5
General Counsel —
class O/S missing
328,000
 — — 09 Mar 2026
3/4/5
William A. Schmitz
3/4/5
Chief Financial Officer —
mixed-class rows
327,908
mixed-class rows
 — — 09 Mar 2026
3/4/5
Leslie Goldman Tepper
3/4/5
Director —
mixed-class rows
303,330
mixed-class rows
 — — 09 Mar 2026
3/4/5
Ian Seth Jacobs
3/4/5
President, CEO, CFO, Secretary, Director —
class O/S missing
275,000
 — — 26 Aug 2025
3/4/5
Blake Janover
3/4/5
Director —
class O/S missing
103,334
 — — 09 Mar 2026
3/4/5
Thomas S. Glanville
3/4/5
Director —
class O/S missing
103,334
 — — 09 Mar 2026
3/4/5

Recent Insider Transactions by Companies or Individuals for DEEP FISSION, INC.

Showing up to 300 most recent insider transactions from the last 12 months.

Insider Symbol Class Transaction % Value $ * Price $ Shares Shares Owned Date Ownership
Blake Janover Restricted Stock Unit Award 3.33% 3,334 103,334 09 Mar 2026 Direct
Elizabeth Muller Employee Stock Option (right to buy) Award 167.7% 2,600,000 4,150,300 09 Mar 2026 Direct
Richard Muller Employee Stock Option (right to buy) Award 34.3% 223,000 872,363 09 Mar 2026 Direct
Michael Allen Brasel Employee Stock Option (right to buy) Award 523.5% 445,000 530,000 09 Mar 2026 Direct
Mark Wayne Peres Employee Stock Option (right to buy) Award 557.5% 223,000 263,000 09 Mar 2026 Direct
Jonathan H. Gordon Employee Stock Option (right to buy) Award 212.4% 223,000 328,000 09 Mar 2026 Direct
William A. Schmitz Employee Stock Option (right to buy) Award 22755.1% 223,000 223,980 09 Mar 2026 Direct
Jonathon Angell Restricted Stock Unit Award 3.33% 3,334 103,334 09 Mar 2026 Direct
Leslie Goldman Tepper Restricted Stock Unit Award 3.33% 3,334 103,334 09 Mar 2026 Direct
Thomas S. Glanville Restricted Stock Unit Award 3.33% 3,334 103,334 09 Mar 2026 Direct
Mark Wayne Peres Employee Stock Option (right to buy) Award 15,000 15,000 19 Feb 2026 Direct
Mark Wayne Peres Restricted Stock Unit Award 25,000 25,000 19 Feb 2026 Direct
Michael Allen Brasel Employee Stock Option (right to buy) Award 15,000 15,000 18 Feb 2026 Direct
William Mark Schmitz Employee Stock Option (right to buy) Award 15,000 15,000 18 Feb 2026 Direct
Jonathan H. Gordon Employee Stock Option (right to buy) Award 20,000 20,000 18 Feb 2026 Direct
Blake Janover Restricted Stock Unit Award 100,000 100,000 19 Dec 2025 Direct
Elizabeth Muller Restricted Stock Units Award 549,451 549,451 09 Dec 2025 Direct
Elizabeth Muller Stock Option (right to buy) Award 22.6% 183,150 994,849 09 Dec 2025 Direct
Thomas S. Glanville Restricted Stock Unit Award 100,000 100,000 12 Nov 2025 Direct
Jonathon Angell Restricted Stock Unit Award 100,000 100,000 12 Nov 2025 Direct
Tepper Leslie Goldman Restricted Stock Units Award 100,000 100,000 12 Nov 2025 Direct
Michael Allen Brasel Employee Stock Option (right to buy) Award 70,000 70,000 07 Nov 2025 Direct
Jonathan H. Gordon Employee Stock Option (right to buy) Award 85,000 85,000 07 Nov 2025 Direct
Richard Muller Common Stock Award 5,196,426 5,196,426 05 Sep 2025 Direct
Elizabeth Muller Common Stock Award 5,057,855 5,057,855 05 Sep 2025 By Muller Family Trust
Elizabeth Muller Common Stock Award 5,196,426 5,196,426 05 Sep 2025 Direct
William Mark Schmitz Common Stock Award 103,928 103,928 05 Sep 2025 Direct
Mark N. Tompkins Common Stock Other -60% -2,833,333 1,891,667 05 Sep 2025 Direct
Mark N. Tompkins Common Stock Sale -0.53% -25,000 4,725,000 26 Aug 2025 Direct
Ian Seth Jacobs Common Stock Purchase 10% 25,000 275,000 26 Aug 2025 Direct
* An asterisk sign (*) next to the price indicates that the price is likely invalid.