CASTLE BIOSCIENCES INC (CSTL) Institutional Ownership Changes & 13F Activity

CASTLE BIOSCIENCES INC (CSTL). Institutional ownership data tracks hedge funds, asset managers, and other institutional investors based on recent SEC Form 13F filings (Q4 2025). This page analyzes institutional buying and selling activity, new holdings, and sold-out positions in the latest reporting period. Notable filers include Rtw Investments, Lp, Portolan Capital Management, Llc, Summit Partners Public Asset Management, Llc, Palisade Capital Management, Lp, and Citadel Advisors Llc.

InstitutionTypeChange in sharesChange Position %SharesReported stock balancePortfolio quarterFiling date
Algert Global LlcSell-38,917-67.2%18,978$738.24KQ4 2025Aug 11, 2026
Hsbc Holdings PlcBuy+19,486—19,486$760.34KQ4 2025Mar 06, 2026
Sunbelt Securities, Inc.Buy+1—1$39.00Q4 2025Feb 20, 2026
Mackenzie Financial CorpBuy+37,317—37,317$1.46MQ4 2025Feb 18, 2026
Summit Global InvestmentsBuy+12,365—12,365$481.00KQ4 2025Feb 18, 2026
Raymond James Financial IncBuy+5,238—5,238$203.76KQ4 2025Feb 18, 2026
Rtw Investments, LpBuy+2,115,237—2,115,237$82.28MQ4 2025Feb 17, 2026
Portolan Capital Management, LlcBuy+1,729,463—1,729,463$67.28MQ4 2025Feb 17, 2026
Summit Partners Public Asset Management, LlcBuy+1,058,725—1,058,725$41.18MQ4 2025Feb 17, 2026
Palisade Capital Management, LpBuy+567,777—567,777$22.09MQ4 2025Feb 17, 2026
Citadel Advisors LlcBuy+366,356—366,356$14.25MQ4 2025Feb 17, 2026
Millennium Management LlcBuy+308,914—308,914$12.02MQ4 2025Feb 17, 2026
Bank Of America CorpBuy+263,019—263,019$10.23MQ4 2025Feb 17, 2026
Northern Trust CorpBuy+262,243—262,243$10.20MQ4 2025Feb 17, 2026
Bridgeway Capital Management, LlcBuy+246,920—246,920$9.61MQ4 2025Feb 17, 2026
Qube Research & Technologies LtdBuy+235,518—235,518$9.16MQ4 2025Feb 17, 2026
Wellington Management Group LlpBuy+218,560—218,560$8.50MQ4 2025Feb 17, 2026
Silvercrest Asset Management Group LlcBuy+205,002—205,002$7.97MQ4 2025Feb 17, 2026
Braidwell LpBuy+177,183—177,183$6.89MQ4 2025Feb 17, 2026
Tudor Investment Corp Et AlBuy+167,178—167,178$6.50MQ4 2025Feb 17, 2026
D. E. Shaw & Co., Inc.Buy+159,709—159,709$6.21MQ4 2025Feb 17, 2026
Parkman Healthcare Partners LlcBuy+150,558—150,558$5.86MQ4 2025Feb 17, 2026
Point72 Asset Management, L.P.Buy+119,458—119,458$4.65MQ4 2025Feb 17, 2026
Two Sigma Investments, LpBuy+84,066—84,066$3.27MQ4 2025Feb 17, 2026
Trexquant Investment LpBuy+64,605—64,605$2.51MQ4 2025Feb 17, 2026
Aqr Capital Management LlcBuy+63,881—63,881$2.48MQ4 2025Feb 17, 2026
Fmr LlcBuy+42,286—42,286$1.64MQ4 2025Feb 17, 2026
Osaic Holdings, Inc.Buy+36,404—36,404$1.42MQ4 2025Feb 17, 2026
Ameriprise Financial IncBuy+35,368—35,368$1.38MQ4 2025Feb 17, 2026
Price T Rowe Associates IncBuy+34,138—34,138$1.33MQ4 2025Feb 17, 2026
Showing 30 of 189

Frequently asked questions about CSTL activity

  • Which institutional owners are buying CSTL?

    Institutional owners buying CSTL include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.

  • What does "buy" mean in CSTL activity?

    "Buy" means an investor increased their reported position in CSTL compared to the prior reporting period. This reflects growing exposure to CASTLE BIOSCIENCES INC (CSTL) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).

  • Is institutional interest in CSTL increasing?

    Institutional interest in CSTL can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.