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Jim Simons's Castle Biosciences, Inc. (CSTL) position

Yes: as of Q1 2026, Jim Simons holds 533K shares of CSTL worth an amount we cannot price (0.0% of the disclosed portfolio). Held since at least Q1 2021; that opening coverage snapshot is not counted as a purchase.
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Current value
an amount we cannot price
Shares held
533K
% of portfolio
0.0%
Quarter-end price
No quarter-end price available

Average buy price is hidden here because at least one covered purchase quarter has no usable local mean price.

CSTL price vs Simons's position

Dates
$23.5$24$24.5$25$25.5← Earlier —11 purchases, 7 sells
Average closing price · filing quarter
Price range · filing quarter

Every quarterly change

Quarter Action Shares change Est. value change Δ Own Shares held Filing date
Q1 2026 Added +40K +8.1% 533K May 14, 2026
Q4 2025 Reduced −70K −12.4% 493K Feb 12, 2026
Q3 2025 Reduced −108K −16.1% 563K Nov 13, 2025
Q2 2025 Reduced −31K −4.4% 670K Aug 13, 2025
Q1 2025 Added +16K +2.4% 701K May 14, 2025
Q4 2024 Added +195K +39.9% 685K Feb 13, 2025
Q3 2024 Added +188K +62.4% 490K Nov 13, 2024
Q2 2024 Added +97K +47.3% 302K Aug 9, 2024
Q1 2024 Added +92K +82.1% 205K May 13, 2024
Q4 2023 Added +6K +5.2% 112K Feb 13, 2024
Q3 2023 Reduced −66K −38.1% 107K Nov 14, 2023
Q2 2023 Added +136K +373.6% 172K Aug 11, 2023
Q1 2023 Added +14K +64.7% 36K May 12, 2023
Q4 2022 Added +5K +30.0% 22K Feb 13, 2023
Q3 2022 Reduced −400 −2.3% 17K Nov 14, 2022
Q2 2022 Reduced −8K −30.4% 17K Aug 12, 2022
Q1 2022 Reduced −109K −81.4% 25K May 13, 2022
Q4 2021 New +134K 134K Feb 11, 2022
Q1 2021 First covered 28K May 13, 2021
Data through Q1 2026 · filed May 14, 2026
19 grouped rows from 19 quarters

More Simons positions

Common questions

Does Jim Simons own CSTL?

Yes. As of Q1 2026, Jim Simons disclosed 533K shares of CSTL, worth an amount we cannot price. All figures come from SEC 13F filings for Q1 2026, the latest disclosed quarter.

When did Jim Simons buy CSTL?

Jim Simons held CSTL since at least Q1 2021, when this filing coverage begins; the opening snapshot is not a disclosed purchase. All figures come from SEC 13F filings for Q1 2026, the latest disclosed quarter.

Did Jim Simons sell CSTL?

The quarter-by-quarter table above shows each sale and reduction Jim Simons disclosed in CSTL. All figures come from SEC 13F filings for Q1 2026, the latest disclosed quarter.

How many shares of CSTL does Jim Simons own?

Jim Simons disclosed 533K shares of CSTL as of Q1 2026. All figures come from SEC 13F filings for Q1 2026, the latest disclosed quarter.

What price did Jim Simons pay for CSTL?

Jim Simons began building the CSTL position before our 13F history starts, so an exact average buy price cannot be estimated without understating it. All figures come from SEC 13F filings for Q1 2026, the latest disclosed quarter.

How are the estimated trade prices calculated?

13F filings disclose quarter-end holdings, not trade dates or execution prices. These estimates use each covered quarter's average market price; the add average excludes the opening position and quarters without price data. All figures come from SEC 13F filings for Q1 2026, the latest disclosed quarter.