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CSTL · Castle Biosciences Inc · Shareholders & Ownership

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$33.08 -0.11 (-0.33%) At close · Oct 23
Market Cap
$1.01B
Shares
30.55M
Volume · Oct 23 203.08K Avg daily vol (3M) 399.95K

Every disclosed holder of CSTL in one list: 13F institutions, Schedule 13D and 13G filers, insiders (Forms 3, 4 and 5) and registered funds, each from its own latest filing. Holders nest by CIK and SEC reporting links, never by name, and each is summed once.

Who Owns CSTL

13F quarter Sep 30, 2026, combined view: filers that have not filed yet carry their Jun 30, 2026 positions
Holder group Shares % Out
Institutional (13F) 27,357,262 89.55%
Insiders (Forms 3, 4, 5) 594,190 1.95%
13D/G-only blocks 425,220 1.39%
Remaining 2,172,835 7.11%
Registered funds (N-PORT, not summed) 9,062,124 29.66%

Shares outstanding: 30,549,507, the issuer's latest cover-page count restated onto today's split basis.

13D/G-only counts each filer's latest 13D or 13G that no 13F report of the listing contains, that names no 13F filer and that no counted insider files. Funds are never summed: their shares sit inside their advisers' 13F reports.

Holders of CSTL

# Holder Shares
1
BlackRock, Inc.
13F CIK 2012383 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
3,291,963
1.1
iShares Russell 2000 ETF
Fund S000004344 · Registered fund · Jun 30, 2026
iShares Trust, not summed
781,367
1.2
iShares Russell 2000 Value ETF
Fund S000004342 · Registered fund · Jun 30, 2026
iShares Trust, not summed
278,685
1.3
iShares Biotechnology ETF
Fund S000004350 · Registered fund · Jun 30, 2026
iShares Trust, not summed
208,267
1.4
BlackRock Advantage Small Cap Core Fund
Fund S000039982 · Registered fund · May 29, 2026
BlackRock Funds, not summed
151,572
1.5
iShares Micro-Cap ETF
Fund S000004439 · Registered fund · Jun 30, 2026
iShares Trust, not summed
100,018
2
RTW INVESTMENTS, LP
13F CIK 1493215 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
2,778,335
3
PRINCIPAL FINANCIAL GROUP INC
13F CIK 1126328 · Insurance company · Jun 30, 2026
carried, not yet filed for the newest quarter
1,726,648
3.1
SmallCap Fund
Fund S000007214 · Registered fund · Jul 31, 2026
Principal Funds, Inc, not summed
725,138
3.2
SmallCap Account
Fund S000007675 · Registered fund · Jun 30, 2026
Principal Variable Contract Funds, Inc, not summed
65,500
3.3
Principal U.S. Small-Cap ETF
Fund S000055159 · Registered fund · Jun 30, 2026
Principal Exchange-Traded Funds, not summed
49,822
3.4
SmallCap Value Fund II
Fund S000007169 · Registered fund · Jul 31, 2026
Principal Funds, Inc, not summed
1,968
4
VANGUARD CAPITAL MANAGEMENT LLC
13F CIK 2100119 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
1,226,497
5
ACADIAN ASSET MANAGEMENT LLC
13F CIK 916542 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
918,668
6
Allianz Asset Management GmbH
13F CIK 1535323 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
879,258
7
VANGUARD TOTAL STOCK MARKET INDEX FUND
Fund S000002848 · Registered fund · Jun 30, 2026
VANGUARD INDEX FUNDS, not summed
852,704
8
VANGUARD PORTFOLIO MANAGEMENT LLC
13F CIK 2100121 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
840,785
9
SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC
13F CIK 1638555 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
824,872
10
STATE STREET CORP
13F CIK 93751 · Bank · Jun 30, 2026
carried, not yet filed for the newest quarter
822,079
10.1
State Street(R) SPDR(R) S&P(R) Health Care Services ETF
Fund S000012331 · Registered fund · Jun 30, 2026
SPDR SERIES TRUST, not summed
68,966
10.2
State Street Institutional Small-Cap Equity Fund
Fund S000001631 · Registered fund · Jun 30, 2026
STATE STREET INSTITUTIONAL FUNDS, not summed
49,283
10.3
STATE STREET SMALL/MID CAP EQUITY INDEX PORTFOLIO
Fund S000050332 · Registered fund · Jun 30, 2026
STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed
10,000
10.4
State Street Small-Cap Equity V.I.S. Fund
Fund S000001636 · Registered fund · Jun 30, 2026
STATE STREET VARIABLE INSURANCE SERIES FUNDS INC, not summed
2,181
10.5
State Street(R) SPDR(R) Portfolio MSCI Global Stock Market ETF
Fund S000036082 · Registered fund · Jun 30, 2026
SPDR INDEX SHARES FUNDS, not summed
1,635
11
GEODE CAPITAL MANAGEMENT, LLC
13F CIK 1214717 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
795,912
12
MACKENZIE FINANCIAL CORP
13F CIK 919859 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
793,507
13
DIMENSIONAL FUND ADVISORS LP
13F CIK 354204 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
791,085
13.1
U.S. SMALL CAP PORTFOLIO
Fund S000000971 · Registered fund · Jul 31, 2026
DFA INVESTMENT DIMENSIONS GROUP INC, not summed
135,065
13.2
U.S. MICRO CAP PORTFOLIO
Fund S000000948 · Registered fund · Jul 31, 2026
DFA INVESTMENT DIMENSIONS GROUP INC, not summed
107,575
13.3
Dimensional U.S. Small Cap ETF
Fund S000070906 · Registered fund · Jul 31, 2026
Dimensional ETF Trust, not summed
87,066
13.4
Dimensional U.S. Core Equity 2 ETF
Fund S000070903 · Registered fund · Jul 31, 2026
Dimensional ETF Trust, not summed
71,710
13.5
U.S. SMALL CAP VALUE PORTFOLIO
Fund S000000987 · Registered fund · Jul 31, 2026
DFA INVESTMENT DIMENSIONS GROUP INC, not summed
63,205
14
Jefferies Financial Group Inc.
13F CIK 96223 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
647,391
15
Qube Research & Technologies Ltd
13F CIK 1729829 · Exempt reporting adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
589,300
16
AIGH Capital Management LLC
13F CIK 1835943 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
545,101
17
Granahan Investment Management, LLC
13G CIK 1026710 · Registered investment adviser · Sep 30, 2024
Rule 13d-1(b), qualified institution
425,220
18
RENAISSANCE TECHNOLOGIES LLC
13F CIK 1037389 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
371,200
19
GOLDMAN SACHS GROUP INC
13F CIK 886982 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
358,397
19.1
Goldman Sachs Small Cap Value Insights Fund
Fund S000014929 · Registered fund · Jul 31, 2026
Goldman Sachs Trust, not summed
82,320
19.2
Goldman Sachs Small Cap Equity Insights Fund
Fund S000009329 · Registered fund · Jul 31, 2026
Goldman Sachs Trust, not summed
35,016
19.3
Goldman Sachs ActiveBeta(R) U.S. Small Cap Equity ETF
Fund S000048296 · Registered fund · May 31, 2026
Goldman Sachs ETF Trust, not summed
30,376
19.4
Goldman Sachs Absolute Return Tracker Fund
Fund S000020314 · Registered fund · Aug 31, 2026
GOLDMAN SACHS TRUST, not summed
11,295
19.5
Goldman Sachs Variable Insurance Trust Small Cap Equity Insights Fund
Fund S000009355 · Registered fund · Jun 30, 2026
Goldman Sachs Variable Insurance Trust, not summed
6,569
20
Point72 Asset Management, L.P.
13F CIK 1603466 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
357,317
21
KENNEDY CAPITAL MANAGEMENT LLC
13F CIK 884589 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
348,371
22
VANGUARD EXTENDED MARKET INDEX FUND
Fund S000002841 · Registered fund · Jun 30, 2026
VANGUARD INDEX FUNDS, not summed
342,655
23
Connor, Clark & Lunn Investment Management Ltd.
13F CIK 1596800 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
331,727
24
MORGAN STANLEY
13F CIK 895421 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
329,684
25
Portolan Capital Management, LLC
13F CIK 1350290 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
328,818
26
PANAGORA ASSET MANAGEMENT INC
13F CIK 883677 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
301,040
27
Allspring Global Investments Holdings, LLC
13F CIK 1890906 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
292,470
27.1
Allspring Emerging Growth Fund
Fund S000015703 · Registered fund · Jul 31, 2026
ALLSPRING FUNDS TRUST, not summed
134,133
27.2
Allspring VT Small Cap Growth Fund
Fund S000007228 · Registered fund · Jun 30, 2026
Allspring VARIABLE TRUST, not summed
131,049
27.3
Allspring Discovery Small Cap Growth Fund
Fund S000029105 · Registered fund · Jun 30, 2025
ALLSPRING FUNDS TRUST, not summed
21,679
28
NORTHERN TRUST CORP
13F CIK 73124 · Bank · Jun 30, 2026
carried, not yet filed for the newest quarter
285,158
28.1
Small Cap Index Fund
Fund S000001245 · Registered fund · Jun 30, 2026
Northern Funds, not summed
15,156
28.2
Small Cap Core Fund
Fund S000001244 · Registered fund · Jun 30, 2026
Northern Funds, not summed
4,942
28.3
FlexShares Morningstar US Market Factor Tilt Index Fund
Fund S000033312 · Registered fund · Jul 31, 2026
FlexShares Trust, not summed
948
29
WASATCH ADVISORS LP
13F CIK 814133 · Registered investment adviser · Sep 30, 2026
279,343
29.1
Wasatch Micro Cap Fund
Fund S000000885 · Registered fund · Jun 30, 2026
WASATCH FUNDS TRUST, not summed
276,685
30
VANGUARD EXPLORER FUND
Fund S000002578 · Registered fund · Jul 31, 2026
VANGUARD EXPLORER FUND, not summed
275,891
31
CITADEL ADVISORS LLC
13F CIK 1423053 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
265,353
32
KORNITZER CAPITAL MANAGEMENT INC /KS
13F CIK 898358 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
264,235
32.1
Buffalo Small Cap Growth Fund
Fund S000022453 · Registered fund · Jun 30, 2026
Buffalo Funds, not summed
239,614
32.2
Buffalo Early Stage Growth Fund
Fund S000006555 · Registered fund · Jun 30, 2026
Buffalo Funds, not summed
23,865
33
SILVERCREST ASSET MANAGEMENT GROUP LLC
13F CIK 1232395 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
256,095
34
CHARLES SCHWAB INVESTMENT MANAGEMENT INC
13F CIK 884546 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
254,535
34.1
Schwab U.S. Small-Cap ETF
Fund S000026636 · Registered fund · May 31, 2026
SCHWAB STRATEGIC TRUST, not summed
138,504
34.2
Schwab Small-Cap Index Fund
Fund S000005912 · Registered fund · Jul 31, 2026
SCHWAB CAPITAL TRUST, not summed
72,750
34.3
Schwab Total Stock Market Index Fund
Fund S000005913 · Registered fund · Jul 31, 2026
SCHWAB CAPITAL TRUST, not summed
19,426
34.4
Schwab U.S. Broad Market ETF
Fund S000026631 · Registered fund · May 31, 2026
SCHWAB STRATEGIC TRUST, not summed
18,371
35
Advisors Capital Management, LLC
13F CIK 1345576 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
238,204
36
NEW YORK STATE COMMON RETIREMENT FUND
13F CIK 810265 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
234,746
37
PALISADE CAPITAL MANAGEMENT, LP
13F CIK 1009006 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
231,931
38
Nuveen, LLC
13F CIK 1871926 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
231,726
38.1
Nuveen Quant Small Cap Equity Fund
Fund S000005386 · Registered fund · Jul 31, 2026
TIAA-CREF Funds, not summed
131,050
38.2
Nuveen Small Cap Blend Index Fund
Fund S000005367 · Registered fund · Jul 31, 2026
TIAA-CREF Funds, not summed
39,751
38.3
Nuveen ESG Small-Cap ETF
Fund S000055815 · Registered fund · Jul 31, 2026
NuShares ETF Trust, not summed
25,475
38.4
Nuveen Equity Index Fund
Fund S000005360 · Registered fund · Jul 31, 2026
TIAA-CREF Funds, not summed
15,802
38.5
Nuveen Life Small Cap Equity Fund
Fund S000005093 · Registered fund · Jun 30, 2026
TIAA-CREF Life Funds, not summed
2,726
39
BRIDGEWAY CAPITAL MANAGEMENT, LLC
13F CIK 1107261 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
221,338
39.1
Omni Small-Cap Value Fund
Fund S000033567 · Registered fund · Jun 30, 2026
Bridgeway Funds, Inc., not summed
79,000
40
Trexquant Investment LP
13F CIK 1633445 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
206,111
41
MILLENNIUM MANAGEMENT LLC
13F CIK 1273087 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
205,369
42
VANGUARD FIDUCIARY TRUST CO
13F CIK 933478 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
197,494
43
VANGUARD STRATEGIC SMALL-CAP EQUITY FUND
Fund S000012432 · Registered fund · Jun 30, 2026
VANGUARD HORIZON FUNDS, not summed
179,326
44
MAETZOLD DEREK J
Insider CIK 1239501 · Oct 19, 2026
Director, Pres. & Chief Exec. Officer, issuer-wide
170,438
45
AQR CAPITAL MANAGEMENT LLC
13F CIK 1167557 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
166,567
45.1
AQR Small Cap Multi-Style Fund
Fund S000040064 · Registered fund · Jun 30, 2026
AQR Funds, not summed
16,750
45.2
AQR Small Cap Momentum Style Fund
Fund S000025644 · Registered fund · Mar 31, 2026
AQR Funds, not summed
2,127
46
VANGUARD RUSSELL 2000 INDEX FUND
Fund S000030003 · Registered fund · May 31, 2026
VANGUARD SCOTTSDALE FUNDS, not summed
147,766
47
FIRST TRUST ADVISORS LP
13F CIK 1125816 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
145,064
48
Parkman Healthcare Partners LLC
13F CIK 1777015 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
144,791
49
Empowered Funds, LLC
13F CIK 1592828 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
142,338
49.1
EA Bridgeway Omni Small-Cap Value ETF
Fund S000078089 · Registered fund · Jun 30, 2026
EA Series Trust, not summed
142,338
50
Advisors Capital Small/Mid Cap Fund
Fund S000070469 · Registered fund · Jun 30, 2026
NEIMAN FUNDS, not summed
135,000

34 more nested rows are not shown here; Every filing lists them all.

Shares are restated onto today's split basis. Change compares each row with the same holder's previous filing in the same source; a dash means there is none to compare. Nested 13D/G, insider and fund rows are not summed, since a 13F report already holds them.

Showing 1–50 of 292 holders

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Key facts CIK 1447362 CUSIP 14843C105 13F (30d) 24 filings 24 filers Visit website Investor relations