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Buy Day today: Good (62) Broad market participation · no major macro event
QSI

QuantumSi Inc

Healthcare · Medical Devices

0.7745$ +6.1% vs. previous close Closing price · As of: Sep 17, 2026

Ownership

Ownership Structure

Who owns QuantumSi Inc (QSI)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 96.6% of the shares are freely tradable; institutional investors hold 29.9%.

Institutional ownership ?Share of the stock held by institutional investors (funds, banks, insurers) according to regulatory filings. 29.9%
Insiders ?Share of the stock held by the executives, founders and major shareholders of the company itself. 10.5%
Float ?Share of stock freely tradable on the market — not locked up in the hands of founders, insiders, or major shareholders. 96.6%
Short % of float ?Shares sold short as a percentage of the freely tradable float — high values signal many bets on falling prices. 8.1%
Shares Outstanding ?Total number of shares issued. Price times share count gives market cap. 199Mio.

Largest Shareholders

Institutions

Institutions QSI
Name Stake (%) Shares Change (%) Date
BlackRock Inc 6.13 13,414,949 +2.8 03/31/2026
Vanguard Capital Management, LLC 3.21 7,021,907 +0.0 03/31/2026
ARK Investment Management LLC 3.14 6,878,899 -2.0 03/31/2026
Amova Asset Management Americas, Inc 1.78 3,885,230 -11.5 06/30/2026
Sumitomo Mitsui Trust Group Inc 1.78 3,885,230 -11.5 06/30/2026
Geode Capital Management, LLC 1.75 3,835,121 -6.8 03/31/2026
State Street Corp 1.72 3,770,689 +5.8 03/31/2026

Funds

Funds QSI
Name Stake (%) Shares Change (%) Date
ARK Genomic Revolution ETF 3.27 7,162,899 -0.3 08/31/2026
ARK Genomic Revolution 3.10 6,794,311 +4.0 06/30/2026
Vanguard MStar Total Stk Mkt Idx Invest 2.45 5,353,930 +0.0 07/31/2026

Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.

Insiders

Insider Transactions

Insider Transactions
Date Person Role Type Shares Price Value
Apr 21, 2026 Jeffry R Keyes CFO Sell 37,381 0.99 37,007
Apr 20, 2026 Jeffrey Alan Hawkins CEO Sell 83,712 1.01 84,549
Apr 20, 2026 Jeffry R Keyes CFO Sell 37,382 1.01 37,756

Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →

Data as of: September 17, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)

Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.

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