$QSI

$1.63 -$0.02 (1.12%) After hours

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

Ownership

13F as of Q2 2026 · 217.8M shares outstanding

Who owns QSI?

By type of holder

Institutions 23.8% Insiders 0.0% Everyone else 76.3%

Concentration Top 10 holders own 23.4%

Rothberg Jonathan M 6.6% · BlackRock, Inc. 2.4%

Institutional ownership

23.8%

-5.2 pts vs last qtr

Institutional holders

140

-17 vs last qtr

Net shares bought

−11.4M

by institutions in Q2 2026

New / sold out

27 / 44

positions opened vs closed

How is ownership changing?

Institutions, last 8 quarters

Biggest buyers in Q2 2026

Millennium Management LLC NEW +3.1M
Jane Street Group, LLC NEW +2.1M

Biggest sellers in Q2 2026

BlackRock, Inc. −8.2M
State Street Corp −2.9M

Who is planning to sell?

Notices of proposed sale, last 12 months

$493K

17 notices from 4 people

Shares covered

503.5K

0.23% of the company

Arranged in advance

of the value is under a 10b5-1 plan

Under a 10b5-1 plan No plan

Largest proposed sellers

Hawkins Jeffrey Alan Officer $261K
Keyes Jeffry R. Officer $107K

Every notice on Red Flags →

A Form 144 is notice of a planned sale, not the sale itself. What insiders actually sold is on Insider Transactions.

Is your stake being diluted?

Diluted share count, FY2019–FY2025

+3742.4%

+83.70% a year

Each share's claim on the business

−97.4%

shrank without buying or selling a share

Spent on buybacks vs paid in stock

— vs $68.9M

over 7 fiscal years

Diluted shares, split-adjusted

Buybacks Stock-based comp

How patient are the owners?

Institutional shares by how long they've been held

5+ years34% 3–5 years42% 1–3 years9% Under 1 year16%

Quarterly turnover

24.3%

of institutional shares changed hands

Top 10 managers, median time held

4.8 years

Super Investors

Investment managers reporting QSI on Form 13F

Holder	Shares	% of company	Change vs last qtr	Held since	% of their book
B BlackRock, Inc.	5.2M	2.40%	−8.2M (−61.0%)	2021	0.0%
Shares held by quarter Peak holding13.4M (Q1'26) Change over 8 quarters−1.7M Share of the company2.400% BlackRock, Inc.'s full portfolio →
VC Vanguard Capital Management LLC	7.6M	3.48%	+556.3K (+7.9%)	2021	0.0%
Shares held by quarter Peak holding7.6M (Q2'26) Change over 8 quarters+7.6M Share of the company3.480% Vanguard Capital Management LLC's full portfolio →

BlackRock, Inc.

5.2M

% of company

2.40%

Change vs last qtr

−8.2M (−61.0%)

Held since

2021

Vanguard Capital Management LLC

7.6M

% of company

3.48%

Change vs last qtr

+556.3K (+7.9%)

Held since

2021

28 more super investors behind a free account

See every manager holding Quantum-Si Inc, how their position has changed, and how long they've held it.

Institutional Funds

Mutual funds and ETFs reporting QSI on Form N-PORT; together they hold 14.1% of the company

Fund	Position value	Shares	% of company	% of the fund	As of
AG ARK Genomic Revolution ETF ARK ETF Trust	$4.82M	6.8M	3.10%	0.31%	July 31, 2026
VT Vanguard Total Stock Market Index Fund Vanguard Index Funds	$4.74M	5.4M	2.46%	0.00%	June 30, 2026

ARK Genomic Revolution ETF

ARK ETF Trust

Position value

$4.82M

% of company

3.10%

% of the fund

0.31%

As of

July 31, 2026

Vanguard Total Stock Market Index Fund

Vanguard Index Funds

Position value

$4.74M

% of company

2.46%

% of the fund

0.00%

As of

June 30, 2026

23 more funds behind a free account

See every fund holding Quantum-Si Inc and how much of the fund the position is.

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
RJ Rothberg Jonathan M 5%+ holder 13D · 7.2%	14.4M	6.60%	—	—	—	—
This holder reports through Schedule 13D/G, not a quarterly 13F. Share of the company6.600% Disclosed stake13D · 7.2% View the 13D/G filing →

Rothberg Jonathan M

5%+ holder13D · 7.2%

14.4M

% of company

6.60%

Change vs last qtr

—

Held since

—

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