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

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. Rothberg23.19%50,765,194$39.60MInsider
4c Holdings I LLC8.20%17,943,750$14.00MInsider
2012 Jmr Trust Common LLC5.70%12,480,108$9.73MInsider
James B. Tananbaum3.85%8,424,317$6.57MInsider
Jeffrey Alan Hawkins1.68%3,669,802$2.86MInsider
John Stark Viii0.90%1,977,368$1.54MInsider
Jeffry R. Keyes0.79%1,724,349$1.34MInsider
Kevin Rakin0.56%1,220,512$952.00kInsider
Christian Lapointe0.54%1,182,429$922.29kInsider
John S. Vieceli0.52%1,140,434$889.54kInsider

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QSI vs Biotech Stocks

TickerInst. %Insider %Net Insider (L12M)Net Insider (L3M)
QSI0.02%48.08%Net BuyingNet Selling
HUMA0.03%11.08%Net BuyingNet Buying
SPRB0.01%99.99%Net SellingNet Buying
MENS0.00%33.35%
CRBU0.05%8.03%Net Selling

Quantum Si Stock Ownership FAQ

Who owns Quantum Si?

Quantum Si (NASDAQ: QSI) is owned by 0.02% institutional shareholders, 48.08% Quantum Si insiders, and 51.89% retail investors. Jonathan M. Rothberg is the largest individual Quantum Si shareholder, owning 50.77M shares representing 23.19% of the company. Jonathan M. Rothberg's Quantum Si shares are currently valued at $38.89M.

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