CSTL · Castle Biosciences Inc · Shareholders & Ownership
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 | As of | Notes |
|---|---|---|---|---|
| 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 |
|
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 |
|
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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