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NASDAQ: QSI
Quantum Si Inc Stock Ownership - Who owns Quantum Si?

OverviewForecastEarningsRevenueDividendOwnership

Insider buying vs selling

Have Quantum Si Inc insiders been buying or selling?

Buy
Sell
NameRoleDateSharesPriceValue
John S. VieceliChief Product Officer2026-06-2315,112$0.90
$13.59kSell
Jeffry R. KeyesChief Financial Officer2026-06-234,117$0.90
$3.70kSell
Christian LapointeGC Corp. Secretary2026-06-237,794$0.90
$7.01kSell
Jeffrey Alan HawkinsPresident CEO2026-06-2311,311$0.90
$10.17kSell
Christian LapointeGC Corp. Secretary2026-06-227,794$0.96
$7.46kSell
John S. VieceliChief Product Officer2026-06-2215,111$0.96
$14.46kSell
Jeffrey Alan HawkinsPresident CEO2026-06-2211,310$0.96
$10.82kSell
Jeffry R. KeyesChief Financial Officer2026-06-224,116$0.96
$3.94kSell
Jeffry R. KeyesChief Financial Officer2026-04-2137,381$1.00
$37.19kSell
Jeffrey Alan HawkinsPresident CEO2026-04-2183,712$1.00
$83.29kSell

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Net Insider Buy/Sell (L12M) Ownership

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QSI Shareholders

What type of owners hold Quantum Si Inc stock?

Institutional
Insider
Retail
NameHoldSharesValueType
Jonathan M. Rothberg23.31%50,765,194$43.76MInsider
4c Holdings I LLC8.24%17,943,750$15.47MInsider
Blackrock Inc6.16%13,414,949$11.56MInstitution
2012 Jmr Trust Common LLC5.73%12,480,108$10.76MInsider
James B. Tananbaum3.87%8,424,317$7.26MInsider
Vanguard Capital Management LLC3.22%7,021,907$6.05MInstitution
Ark Investment Management LLC3.16%6,878,899$5.93MInstitution
Sumitomo Mitsui Trust Group Inc2.02%4,391,666$3.79MInstitution
Amova Asset Management Americas Inc2.02%4,391,666$3.79MInstitution
Geode Capital Management LLC1.76%3,835,121$3.31MInstitution

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QSI vs Biotech Stocks

TickerInst. %Insider %Net Insider (L12M)Net Insider (L3M)
QSI28.97%48.33%Net BuyingNet Selling
KRRO29.12%70.88%Net BuyingNet Selling
PRQR32.57%1.95%Net BuyingNet Buying
OTLK4.87%95.13%Net BuyingNet Buying
ARCT85.46%12.98%Net Buying
View Top Biotech Stocks

Quantum Si Stock Ownership FAQ

Who owns Quantum Si?

Quantum Si (NASDAQ: QSI) is owned by 28.97% institutional shareholders, 48.33% Quantum Si insiders, and 22.70% retail investors. Jonathan M. Rothberg is the largest individual Quantum Si shareholder, owning 50.77M shares representing 23.31% of the company. Jonathan M. Rothberg's Quantum Si shares are currently valued at $41.58M.

If you're new to stock investing, here's how to buy Quantum Si stock.
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