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
Jonathan M. RothbergDirector2025-10-1626,095$3.07
$80.11kSell
Christian LapointeGC Corp. Secretary2025-09-235,364$1.64
$8.77kSell
Jeffry R. KeyesChief Financial Officer2025-09-233,873$1.64
$6.33kSell
John S. VieceliChief Product Officer2025-09-239,843$1.64
$16.09kSell
Todd C. BennettChief Commercial Officer2025-09-2318,482$1.64
$30.22kSell
Jeffrey Alan HawkinsPresident CEO2025-09-2310,643$1.64
$17.40kSell
Todd C. BennettChief Commercial Officer2025-09-2218,482$1.68
$31.11kSell
Jeffrey Alan HawkinsPresident CEO2025-09-2210,643$1.68
$17.91kSell
Jeffry R. KeyesChief Financial Officer2025-09-223,873$1.68
$6.52kSell
Christian LapointeGC Corp. Secretary2025-09-225,364$1.68
$9.03kSell

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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. Rothberg23.56%50,765,194$69.55MInsider
4c Holdings I LLC8.33%17,943,750$24.58MInsider
2012 Jmr Trust Common LLC5.79%12,480,108$17.10MInsider
Blackrock Inc5.25%11,321,673$15.51MInstitution
Vanguard Group Inc4.04%8,714,507$11.94MInstitution
James B. Tananbaum3.91%8,424,317$11.54MInsider
Ark Investment Management LLC3.54%7,624,042$10.44MInstitution
Sumitomo Mitsui Trust Group Inc2.42%5,217,499$7.15MInstitution
Amova Asset Management Americas Inc2.42%5,217,499$7.15MInstitution
Geode Capital Management LLC1.74%3,747,169$5.13MInstitution

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QSI vs Biotech Stocks

TickerInst. %Insider %Net Insider (L12M)Net Insider (L3M)
QSI29.91%47.56%Net SellingNet Selling
RLMD10.55%4.77%Net BuyingNet Buying
LRMR56.60%43.40%Net Buying
KYTX50.14%49.86%
ALDX63.63%27.77%Net Selling

Quantum Si Stock Ownership FAQ

Who owns Quantum Si?

Quantum Si (NASDAQ: QSI) is owned by 29.91% institutional shareholders, 47.56% Quantum Si insiders, and 22.53% retail investors. Jonathan M. Rothberg is the largest individual Quantum Si shareholder, owning 50.77M shares representing 23.56% of the company. Jonathan M. Rothberg's Quantum Si shares are currently valued at $69.55M.

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