Castle Biosciences Inc (CSTL) Institutional Ownership

Institutions by Trading Activity

Ownership Statistics

29,073,000Shares Outstanding

27,557,868Shares held by institutions

$677,372,395Value of institutional holdings

94.79%Institutional ownership %

4.85%Shares Changed QoQ

191No. of institutional investors

Shares Owned by Institutions

Shares Purchased/Sold by Institutions

Ownership Summary

Castle Biosciences Inc (NASDAQ:CSTL) appears in 191 institutional 13F filings for the quarter ending December 2025.

These investors collectively held 93.7% of Castle Biosciences's outstanding shares in December 2025, up from 93.1% in September 2025.
Their total shares held in CSTL increased 4.18% from the prior quarter, while the number of investors in Castle Biosciences decreased 0.52% year over year.
Among the 191 funds, 104 bought more Castle Biosciences shares, 69 sold down, and 18 held their ground.
Combined, these investors held 27.25Mn shares in CSTL for December 2025, up by 1.09Mn shares quarter on quarter, and up 241.83K shares year over year.
As of December 31, 2025, BlackRock, Inc. held the largest stake in Castle Biosciences with 3.11Mn shares, accounting for 10.68% of total shares outstanding.
The biggest buyers of Castle Biosciences 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), Goldman Sachs Group Inc (229.37K), WELLINGTON MANAGEMENT GROUP LLP (218.56K).
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).
Castle Biosciences's 10 largest shareholders as of 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) per Business Quant data.

191 Institutional Holders

27,557,868 Total Shares Held

Rows:

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Owner Name	Date	Shares Held	Change (QoQ)	Change (%)	Value (USD)
BlackRock, Inc.	31 Dec, 2025	3,105,246	-84,650	-2.65%	$120,794,069.00
VANGUARD GROUP INC	31 Dec, 2025	2,199,829	27,511	1.27%	$85,573,349.00
RTW INVESTMENTS, LP	31 Dec, 2025	2,115,237	2,115,237	0.00%	$82,282,719.00
Principal Financial Group Inc	31 Dec, 2025	1,807,644	13,289	0.74%	$70,317,352.00
Portolan Capital Management, LLC	31 Dec, 2025	1,729,463	214,352	14.15%	$67,276,111.00
DIMENSIONAL FUND ADVISORS LP	31 Dec, 2025	1,143,799	-330,290	-22.41%	$44,494,673.00
SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC	31 Dec, 2025	1,058,725	658,725	164.68%	$41,184,403.00
State Street Corp	31 Dec, 2025	736,454	12,374	1.71%	$28,648,061.00
GEODE CAPITAL MANAGEMENT, LLC	31 Dec, 2025	714,913	16,303	2.33%	$27,814,871.00
AIGH Capital Management LLC	31 Dec, 2025	624,719	-82,568	-11.67%	$24,301,569.00
Allianz Asset Management GmbH	31 Dec, 2025	622,299	-26,052	-4.02%	$24,207,431.00
Goldman Sachs Group Inc	31 Dec, 2025	574,470	229,371	66.47%	$22,346,882.00
PALISADE CAPITAL MANAGEMENT, LP	31 Dec, 2025	567,777	-70,879	-11.10%	$22,086,525.00
WASATCH ADVISORS LP	31 Dec, 2025	537,241	-131,879	-19.71%	$20,898,675.00
Nuveen, LLC	31 Dec, 2025	524,681	-432,400	-45.18%	$20,410,091.00
RENAISSANCE TECHNOLOGIES LLC	31 Dec, 2025	493,100	-69,500	-12.35%	$19,181,590.00
SCHRODER INVESTMENT MANAGEMENT GROUP	31 Dec, 2025	492,161	-2,789	-0.56%	$19,346,849.00
ACADIAN ASSET MANAGEMENT LLC	31 Dec, 2025	390,406	-61,246	-13.56%	$15,180.00
Connor, Clark & Lunn Investment Management Ltd.	31 Dec, 2025	388,491	52,600	15.66%	$15,112,300.00
CITADEL ADVISORS LLC	31 Dec, 2025	366,356	115,441	46.01%	$14,251,249.00

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