Castle Biosciences Inc (CSTL) Institutional Ownership

Institutions by Trading Activity

Ownership Statistics

0Shares Outstanding

476,757Shares held by institutions

$11,232,395Value of institutional holdings

88.42%Institutional ownership %

8.78%Shares Changed QoQ

148No. of institutional investors

Shares Owned by Institutions

Shares Purchased/Sold by Institutions

Ownership Summary

Castle Biosciences Inc (NASDAQ:CSTL) is held by 191 institutional investors per 13F filings through December 2025.

These investors collectively held 93.7% of Castle Biosciences's outstanding shares in December 2025, up from 93.1% in September 2025.
They increased total shares held in Castle Biosciences by 4.18% from last quarter, and the number of investors in CSTL decreased 0.52% annually.
Of these 191 funds, 104 grew their exposure to Castle Biosciences, 69 cut back, and 18 maintained positions.
In total, institutional investors held 27.25Mn shares in Castle Biosciences as of December 2025, up by 1.09Mn shares quarter on quarter, and up 241.83K shares year over year.
BlackRock, Inc. leads ownership in CSTL with 3.11Mn shares as of December 31, 2025, equal to 10.68% of outstanding shares.
Top purchasers of CSTL stock for the quarter ending December 2025 included RTW INVESTMENTS, LP (2.12Mn), SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC (658.72K), EVENTIDE ASSET MANAGEMENT, LLC (305.0K), WELLINGTON MANAGEMENT GROUP LLP (218.56K), Portolan Capital Management, LLC (214.35K).
The largest sellers of Castle Biosciences for the quarter ending December 2025 were BRAIDWELL LP (645.55K), Nuveen, LLC (432.4K), Bank Of America Corp /De/ (367.72K), DIMENSIONAL FUND ADVISORS LP (330.29K), MILLENNIUM MANAGEMENT LLC (266.18K).
Per Business Quant, the top 10 investors in CSTL for the quarter ending December 2025 include BlackRock, Inc. (3.11Mn), VANGUARD GROUP INC (2.2Mn), RTW INVESTMENTS, LP (2.12Mn), Principal Financial Group Inc (1.81Mn), Portolan Capital Management, LLC (1.73Mn), DIMENSIONAL FUND ADVISORS LP (1.14Mn), SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC (1.06Mn), State Street Corp (736.45K), GEODE CAPITAL MANAGEMENT, LLC (714.91K), AIGH Capital Management LLC (624.72K).

191 Institutional Holders

476,757 Total Shares Held

Rows:

Download Data

Owner Name	Date	Change (QoQ)	Change (%)	Value (USD)
BlackRock, Inc.	31 Dec, 2025	-84,650	-2.65%	$0.00
VANGUARD GROUP INC	31 Dec, 2025	27,511	1.27%	$0.00
SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC	31 Dec, 2025	658,725	164.68%	$0.00
Barclays Plc	31 Dec, 2025	-53,220	-42.45%	$0.00
RTW INVESTMENTS, LP	31 Dec, 2025	2,115,237	0.00%	$0.00
AIGH Capital Management LLC	31 Dec, 2025	-82,568	-11.67%	$0.00
HSBC HOLDINGS PLC	31 Dec, 2025	5,739	17.27%	$0.00
Principal Financial Group Inc	31 Dec, 2025	13,289	0.74%	$0.00
Nuveen, LLC	31 Dec, 2025	-432,400	-45.18%	$0.00
Rockefeller Capital Management L.P.	31 Dec, 2025	174	0.00%	$0.00
Portolan Capital Management, LLC	31 Dec, 2025	214,352	14.15%	$0.00
Qube Research & Technologies Ltd	31 Dec, 2025	14,557	6.59%	$0.00
DIMENSIONAL FUND ADVISORS LP	31 Dec, 2025	-330,290	-22.41%	$0.00
BRAIDWELL LP	31 Dec, 2025	-645,552	-78.46%	$0.00
State Street Corp	31 Dec, 2025	12,374	1.71%	$0.00
Allspring Global Investments Holdings, LLC	31 Dec, 2025	2,658	1.70%	$0.00
GEODE CAPITAL MANAGEMENT, LLC	31 Dec, 2025	16,303	2.33%	$0.00
UBS Group AG	31 Dec, 2025	-149,489	-51.31%	$0.00
Allianz Asset Management GmbH	31 Dec, 2025	-26,052	-4.02%	$0.00
Point72 Asset Management, L.P.	31 Dec, 2025	-217,500	-64.55%	$0.00

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