QUANTUM-SI INC (QSI) Institutional Shareholders
QUANTUM-SI INC (QSI) is currently reported in institutional portfolios tracked by InsiderSet based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026. The institutional investors covered on this page collectively reported approximately $46.79M in QSI holdings during the latest filing period.
Vanguard Capital Management Llc is currently the largest disclosed institutional shareholder of QSI tracked by InsiderSet, reporting ownership valued at approximately $6.71M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $5.65M, representing an estimated loss of -15.81% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 76% of the total disclosed QSI value among the investors covered in this analysis. Major shareholders include Vanguard Capital Management Llc, ARK Invest, Blackrock, Inc., and several other long-term asset managers with concentrated positions in QUANTUM-SI INC (QSI).
This page ranks the largest institutional QSI shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
140
Total Reported Value
$46.79M
Largest Holder
Vanguard Capital Management Llc
Largest Position
$6.71M
Insider Transactions (90d)
8
Latest Filing Quarter
Q2 2026
New Institutional Positions
128
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Vanguard Capital Management Llc | 0.00% | 7,578,208 | $6,706,714 | $5,646,523 | -$1,060,191 | -15.81% | |
| ARK Invest | Cathie Wood | 0.04% | 7,167,738 | $6,343,448 | $5,340,682 | -$1,002,766 | -15.81% |
| Blackrock, Inc. | 0.00% | 5,225,352 | $4,624,436 | $3,893,410 | -$731,026 | -15.81% | |
| Amova Asset Management Americas, Inc. | 0.04% | 3,885,230 | $3,457,855 | $2,894,885 | -$562,970 | -16.28% | |
| Sumitomo Mitsui Trust Group, Inc. | 0.00% | 3,885,230 | $3,438,429 | $2,894,885 | -$543,544 | -15.81% | |
| Millennium Management Llc | 0.00% | 3,131,726 | $2,771,578 | $2,333,449 | -$438,129 | -15.81% | |
| Ubs Group Ag | 0.00% | 2,561,897 | $2,267,279 | $1,908,869 | -$358,410 | -15.81% | |
| Aqr Capital Management Llc | 0.00% | 2,348,665 | $2,078,569 | $1,749,990 | -$328,579 | -15.81% | |
| Geode Capital Management, Llc | 0.00% | 2,236,526 | $1,980,439 | $1,666,436 | -$314,003 | -15.86% | |
| Jane Street Group, Llc | 0.00% | 2,142,735 | $1,896,320 | $1,596,552 | -$299,768 | -15.81% | |
| Susquehanna International Group, Llp | 0.00% | 1,116,750 | $988,324 | $832,090 | -$156,234 | -15.81% | |
| Vanguard Fiduciary Trust Co | 0.00% | 1,116,683 | $988,264 | $832,041 | -$156,223 | -15.81% | |
| State Street Corp | 0.00% | 890,741 | $788,306 | $663,691 | -$124,615 | -15.81% | |
| Fosun International Ltd | 0.15% | 743,935 | $658,382 | $554,306 | -$104,076 | -15.81% | |
| Renaissance Technologies LLC | Jim Simons | 0.00% | 553,871 | $490,176 | $412,689 | -$77,487 | -15.81% |
| Vanguard Portfolio Management Llc | 0.00% | 497,098 | $439,932 | $370,388 | -$69,544 | -15.81% | |
| Goldman Sachs Group Inc | 0.00% | 476,288 | $421,515 | $354,882 | -$66,633 | -15.81% | |
| Northern Trust Corp | 0.00% | 450,531 | $398,720 | $335,691 | -$63,029 | -15.81% | |
| Invesco Ltd. | 0.00% | 443,929 | $392,877 | $330,771 | -$62,106 | -15.81% | |
| Bnp Paribas Financial Markets | 0.00% | 398,598 | $352,759 | $296,995 | -$55,764 | -15.81% | |
| Ieq Capital, Llc | 0.00% | 350,816 | $310,472 | $261,393 | -$49,079 | -15.81% | |
| Aster Capital Management (Difc) Ltd | 0.06% | 344,510 | $304,891 | $256,694 | -$48,197 | -15.81% | |
| Morgan Stanley | 0.00% | 323,482 | $286,282 | $241,026 | -$45,256 | -15.81% | |
| Iq Eq Fund Management (Ireland) Ltd | 0.02% | 321,134 | $284,204 | $239,277 | -$44,927 | -15.81% | |
| Knollwood Investment Advisory, Llc | 0.02% | 300,000 | $265,500 | $223,530 | -$41,970 | -15.81% | |
| Imc-Chicago, Llc | 0.00% | 285,758 | $252,896 | $212,918 | -$39,978 | -15.81% | |
| Bridgeway Capital Management, Llc | 0.00% | 206,100 | $182,399 | $153,565 | -$28,834 | -15.81% | |
| Barclays Plc | 0.00% | 205,690 | $182,035 | $153,260 | -$28,775 | -15.81% | |
| Xtx Topco Ltd | 0.00% | 177,680 | $157,247 | $132,389 | -$24,858 | -15.81% | |
| Simplex Trading, Llc | 0.00% | 165,293 | $146,284 | $123,160 | -$23,124 | -15.81% | |
| Verdence Capital Advisors Llc | 0.01% | 158,305 | $140,100 | $117,953 | -$22,147 | -15.81% | |
| Mariner, Llc | 0.00% | 157,689 | $139,553 | $117,494 | -$22,059 | -15.81% | |
| Shay Capital Llc | 0.01% | 150,922 | $133,566 | $112,452 | -$21,114 | -15.81% | |
| Fmr Llc | 0.00% | 123,767 | $109,534 | $92,219 | -$17,315 | -15.81% | |
| Cwm, Llc | 0.00% | 126,632 | $98,013 | $94,354 | -$3,659 | -3.73% | |
| Group One Trading Llc | 0.00% | 107,473 | $95,114 | $80,078 | -$15,036 | -15.81% | |
| Jones Financial Companies Lllp | 0.00% | 100,483 | $85,812 | $74,870 | -$10,942 | -12.75% | |
| Hrt Financial Lp | 0.00% | 93,647 | $82,000 | $69,776 | -$12,224 | -14.91% | |
| Alphacore Capital Llc | 0.00% | 89,368 | $79,091 | $66,588 | -$12,503 | -15.81% | |
| Cerity Partners Llc | 0.00% | 85,347 | $75,533 | $63,592 | -$11,941 | -15.81% | |
| Vanguard Global Advisers, Llc | 0.00% | 84,757 | $75,010 | $63,152 | -$11,858 | -15.81% | |
| Charles Schwab Investment Management Inc | 0.00% | 84,612 | $74,882 | $63,044 | -$11,838 | -15.81% | |
| Y-Intercept (Hong Kong) Ltd | 0.00% | 79,089 | $69,994 | $58,929 | -$11,065 | -15.81% | |
| Jtc Employer Solutions Trustee Ltd | 0.01% | 77,787 | $69,000 | $57,959 | -$11,041 | -16.00% | |
| Mercer Global Advisors Inc | 0.00% | 77,277 | $68,390 | $57,579 | -$10,811 | -15.81% | |
| Rhumbline Advisers | 0.00% | 75,989 | $67,249 | $56,619 | -$10,630 | -15.81% | |
| Winton Group Ltd | 0.00% | 75,800 | $67,083 | $56,479 | -$10,604 | -15.81% | |
| Captrust Financial Advisors | 0.00% | 73,128 | $64,718 | $54,488 | -$10,230 | -15.81% | |
| Hollencrest Capital Management | 0.00% | 65,011 | $57,535 | $48,440 | -$9,095 | -15.81% | |
| Gsa Capital Partners Llp | 0.00% | 60,011 | $53,000 | $44,714 | -$8,286 | -15.63% |
Frequently asked questions about QSI
Who owns the most QSI stock?
The largest holders of QSI are typically major institutional investors such as asset managers and hedge funds reporting on Form 13F. The table above ranks tracked superinvestors by reported position size using the latest available filings for QUANTUM-SI INC (QSI).
Is QSI widely held by superinvestors?
Many widely followed stocks like QSI appear across numerous superinvestor portfolios because of liquidity, index inclusion, and fundamentals. The holder count and table above show how broadly QSI is represented among the institutional managers we track.
What do “Current Estimated Value”, “Gain/loss Since Filing”, and “Estimated Portfolio Performance” mean?
Current Estimated Value is reported share quantity from the latest 13F times our most recent split-adjusted U.S. session close. Gain/loss Since Filing is that estimate minus the reported 13F dollar value; Estimated Portfolio Performance is that difference as a percent of the reported value. Green means the estimate is above the filing value; red means below (not purchase cost). If many filers share the same implied filing price per share, the performance % may match across rows. These are not official fund marks or live quotes.