Citadel Advisors
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Citadel Advisors’s Quantum-Si Incorporated QSI Stock Holding History

Citadel Advisors’s Portfolio QSI Stock Details QSI Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q2 		$39.2K Buy
44,335
+28,789
+185% +$27.4K ﹤0.01% 13232
2026
Q1 		$12K Sell
15,546
-2,660,551
-99% -$2.76M ﹤0.01% 12734
2025
Q4 		$2.94M Buy
2,676,097
+2,269,050
+557% +$3.69M ﹤0.01% 5198
2025
Q3 		$574K Sell
407,047
-151,260
-27% -$219K ﹤0.01% 8793
2025
Q2 		$1.09M Buy
558,307
+419,809
+303% +$621K ﹤0.01% 6896
2025
Q1 		$166K Buy
+138,498
New +$265K ﹤0.01% 10711
2024
Q4 		– Sell
-79,753
Closed -$93.5K – 15224
2024
Q3 		$70.4K Sell
79,753
-146,547
-65% -$142K ﹤0.01% 11552
2024
Q2 		$238K Buy
226,300
+133,300
+143% +$214K ﹤0.01% 9581
2024
Q1 		$183K Sell
93,000
-32,130
-26% -$56.1K ﹤0.01% 10451
2023
Q4 		$252K Buy
+125,130
New +$191K ﹤0.01% 9511
2023
Q3 		– Sell
-107,111
Closed -$258K – 14954
2023
Q2 		$192K Buy
107,111
+76,478
+250% +$120K ﹤0.01% 9961
2023
Q1 		$53.9K Sell
30,633
-114,151
-79% -$225K ﹤0.01% 12059
2022
Q4 		$265K Sell
144,784
-21,346
-13% -$55K ﹤0.01% 9584
2022
Q3 		$457K Sell
166,130
-124,015
-43% -$396K ﹤0.01% 8661
2022
Q2 		$673K Buy
290,145
+248,460
+596% +$952K ﹤0.01% 7979
2022
Q1 		$195K Buy
41,685
+20,271
+95% +$98.8K ﹤0.01% 11576
2021
Q4 		$168K Buy
+21,414
New +$161K ﹤0.01% 12114
2021
Q3 		– Sell
-867,703
Closed -$8.54M – 14487
2021
Q2 		$10.5M Buy
+867,703
New +$9.09M ﹤0.01% 2997

Other funds holding QSI

Vanguard Capital Management
Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM
AIM
ARK Investment Management St. Petersburg, Florida $15.4B AUM 50.29% 1-Year Est. Return
BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
NAMA
Nikko Asset Management Americas New York $7.75B AUM 33.73% 1-Year Est. Return
Sumitomo Mitsui Trust Group
Sumitomo Mitsui Trust Group Minato-Ku, Tokyo, Japan $175B AUM 40.63% 1-Year Est. Return
Millennium Management
Millennium Management New York $276B AUM 44.8% 1-Year Est. Return
UBS Group
UBS Group Zurich, Switzerland $786B AUM 40.34% 1-Year Est. Return
AQR Capital Management
AQR Capital Management Greenwich, Connecticut $287B AUM 42.33% 1-Year Est. Return
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return
Jane Street
Jane Street New York $1.21T AUM 78.12% 1-Year Est. Return

Citadel Advisors's QSI Position: Q2 2026 in Review

Citadel Advisors increased its Quantum-Si Incorporated (QSI) stake by 185% in Q2 2026, buying an estimated $27.4K and bringing the position to 44,335 shares worth $39.2K. The position accounts for ﹤0.01% of the portfolio, ranked #13232.

Citadel Advisors first reported a position in QSI in Q2 2021 and has held it in 18 quarters since. The position peaked at $10.5M in Q2 2021. 141 funds tracked by Wall St. Rank hold QSI as of Q2 2026.

  • Citadel Advisors held 44,335 shares of Quantum-Si Incorporated worth $39.2K as of Q2 2026.
  • Citadel Advisors bought 28,789 Quantum-Si Incorporated shares in Q2 2026, an estimated $27.4K.
  • Quantum-Si Incorporated made up ﹤0.01% of Citadel Advisors's portfolio in Q2 2026, its #13232 holding.
  • Citadel Advisors first reported a position in Quantum-Si Incorporated in Q2 2021 and has held it in 18 quarters since.
  • Citadel Advisors's Quantum-Si Incorporated position peaked at $10.5M in Q2 2021.
  • 141 funds tracked by Wall St. Rank held Quantum-Si Incorporated as of Q2 2026.

Based on Citadel Advisors's 13F filing for Q2 2026, filed 14 Aug 2026.