How many institutional investors hold QSI?

3 tracked institutional investors disclosed a position in QSI (QUANTUM-SI INC) in their most recent 13F filing.

Who is the largest institutional holder of QSI?

Cathie Wood, ARK Investment Management, holds the largest disclosed position in QSI, valued at $5M.

Where does this QSI ownership data come from?

SEC Form 13F-HR filings, accessed via EDGAR. 13F filings are disclosed quarterly with a 45-day reporting delay and cover U.S.-listed long equity positions only. This is not investment advice.

QSI — QUANTUM-SI INC

Name: QUANTUM-SI INC (QSI) — Institutional Ownership
Creator: InvestorLens
License: https://www.sec.gov/about/website-policies

Public company

For educational research only.InvestorLens analyzes public regulatory filings (SEC EDGAR, STOCK Act PTRs) that may be delayed by 45 days or more. Information shown is historical and is not financial, legal, or tax advice, nor a recommendation or solicitation to buy or sell any security. Always do your own research.

InvestorLens aggregates public filing data to show which tracked investors reported holdings in this stock. Dollar values represent reported position values, not market capitalization, and may be delayed up to 45 days. Not a recommendation.

Sourced from SEC EDGAR public filings

About QUANTUM-SI INC (QSI)

QUANTUM-SI INC (QSI) appears in the most recent 13F filings of 3 tracked institutional investors. The largest disclosed position is held by Cathie Wood (ARK Investment Management), valued at $5M. Across recent filings, tracked investors recorded 1 new positions, 0 increased, 0 reduced, and 0 exited. All data sourced from SEC 13F filings.

Smart Money Consensus™

Based on recent institutional activity in QSI

100

/100

Strong Institutional Accumulation

Added / Increased1

Reduced0

Exited0

BearishBullish

Crowded Trade Score™

How many top investors track QSI

/100

Emerging Interest

3investors

A small number of top investors own this.

UndiscoveredCrowded

151015+

QSI Ownership Composition

How QUANTUM-SI INC is held across tracked investor types, based on reported 13F positions.

Dominant Type

Growth Funds

93% of tracked value

Institutions

tracked investors

Total Reported

$5.7M

combined 13F value

Growth Funds93.3%
Other6.7%

Growth Funds(1)

93.3%

Other(2)

6.7%

Tracked investors reporting QSI

Investor	Firm	Shares	Market value	% of portfolio	As of
Cathie Wood	ARK Investment Management	6.9M	$5.3M	0.04%	Mar 31, 2026
Izzy Englander	Millennium Management	191.8K	$211K	0.00%	Dec 31, 2025
Ken Griffin	Citadel Advisors	219.5K	$169.9K	0.00%	Mar 31, 2026

Cathie WoodMar 31, 2026
ARK Investment Management
Shares
6.9M
Value
$5.3M
% Portfolio
0.04%
Izzy EnglanderDec 31, 2025
Millennium Management
Shares
191.8K
Value
$211K
% Portfolio
0.00%
Ken GriffinMar 31, 2026
Citadel Advisors
Shares
219.5K
Value
$169.9K
% Portfolio
0.00%

Recent activity

Investor	Action	Δ %	Current value	Filing date
Cathie Wood	New	—	$5.3M	May 12, 2026

Cathie Wood
New
$5.3MMay 12, 2026

Frequently asked questions

How many institutional investors hold QSI?: 3 tracked institutional investors disclosed a position in QSI (QUANTUM-SI INC) in their most recent 13F filing.
Who is the largest institutional holder of QSI?: Cathie Wood, ARK Investment Management, holds the largest disclosed position in QSI, valued at $5M.
Did institutional ownership of QSI increase or decrease?: Across recent 13F filings, tracked investors recorded 1 new positions, 0 increased, 0 reduced, and 0 fully exited QSI.
Where does this QSI ownership data come from?: SEC Form 13F-HR filings, accessed via EDGAR. 13F filings are disclosed quarterly with a 45-day reporting delay and cover U.S.-listed long equity positions only. This is not investment advice.