$FISN

$2.69 +$0.53 (24.54%) Close

$FISN Overview Financial Statements SEC Filings Executives News Red Flags Capital Raising Ownership Insider Transactions Congressional Trades

Ownership

13F as of Q2 2026 · 58.9M shares outstanding

Who owns FISN?

By type of holder

Institutions 3.9% Insiders 96.1% Everyone else 0.0%

Concentration Top 10 holders own 74.5%

Tompkins Mark N. 32.1% · Muller Elizabeth 17.9%

Institutional ownership

3.9%

+3.9 pts vs last qtr

Institutional holders

+21 vs last qtr

Net shares bought

+2.3M

by institutions in Q2 2026

New / sold out

21 / 0

positions opened vs closed

How is ownership changing?

Institutions, last 8 quarters

Biggest buyers in Q2 2026

Blue Owl Capital Holdings LP NEW +1.3M
Elevation Wealth Management LLC NEW +298.3K

Biggest sellers in Q2 2026

None.

Who is planning to sell?

No insider has filed a notice of proposed sale (Form 144) for Deep Fission, Inc in the last 12 months.

Is your stake being diluted?

There are not yet two fiscal years of reported share counts for Deep Fission, Inc.

How patient are the owners?

Institutional shares by how long they've been held

5+ years0% 3–5 years0% 1–3 years0% Under 1 year100%

Quarterly turnover

—

of institutional shares changed hands

Top 10 managers, median time held

0 quarters

Super Investors

Investment managers reporting FISN on Form 13F

Holder	Shares	% of company	Change vs last qtr	Held since	% of their book
BO Blue Owl Capital Holdings LP	1.3M	2.26%	NEW	Q2 '26	2.2%
Shares held by quarter Peak holding1.3M (Q2'26) Change over 8 quarters+1.3M Share of the company2.260% Blue Owl Capital Holdings LP's full portfolio →
EW Elevation Wealth Management LLC	298.3K	0.51%	NEW	Q2 '26	2.5%
Shares held by quarter Peak holding298.3K (Q2'26) Change over 8 quarters+298.3K Share of the company0.510% Elevation Wealth Management LLC's full portfolio →

Blue Owl Capital Holdings LP

1.3M

% of company

2.26%

Change vs last qtr

NEW

Held since

Q2 '26

Elevation Wealth Management LLC

298.3K

% of company

0.51%

Change vs last qtr

NEW

Held since

Q2 '26

19 more super investors behind a free account

See every manager holding Deep Fission, Inc, how their position has changed, and how long they've held it.

Institutional Funds

Mutual funds and ETFs reporting FISN on Form N-PORT; together they hold 0.0% of the company

Fund	Position value	Shares	% of company	% of the fund	As of
FN Fidelity Nasdaq Composite Index Fund Fidelity Concord Street Trust	$123K	18.3K	0.03%	0.00%	August 31, 2026

Fidelity Nasdaq Composite Index Fund

Fidelity Concord Street Trust

Position value

$123K

% of company

0.03%

% of the fund

0.00%

As of

August 31, 2026

Insiders and 5%+ holders

From Forms 3/4/5 and Schedules 13D/G

Holder	Shares	% of company	Change vs last qtr	8 quarters	Held since	% of their book
TM Tompkins Mark N. Insider	18.9M	32.11%	—	—	—	—
Insider holdings come from Form 3/4/5 filings, which are not quarterly. Share of the company32.110% Tompkins Mark N.'s insider activity →
ME Muller Elizabeth 5%+ holder 13D · 20.6%	10.5M	17.90%	—	—	—	—
This holder reports through Schedule 13D/G, not a quarterly 13F. Share of the company17.900% Disclosed stake13D · 20.6% View the 13D/G filing →

Tompkins Mark N.

Insider

18.9M

% of company

32.11%

Change vs last qtr

—

Held since

—

Muller Elizabeth

5%+ holder13D · 20.6%

10.5M

% of company

17.90%

Change vs last qtr

—

Held since

—

6 more holders behind a free account

See every insider and 5%+ holder of Deep Fission, Inc.

Comments