Latest Period
Q4 2025
Security Snapshot
CASTLE BIOSCIENCES INC - Common Stock (CSTL) Institutional Ownership
CUSIP: 14843C105
13F Institutional Holders and Ownership History from Q3 2019 to Q1 2026
Institutions Reporting
195
Shares (Excl. Options)
27,312,139
Price
$38.90
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- Type / Class
- Equity / Common Stock
- Symbol
- CSTL on Nasdaq
- Shares outstanding
- 29,378,292
- Price per share
- $24.55
- All holders as of 31 Dec 2025
- Q4 2025
- Total 13F shares
- 27,312,139
- Total reported value
- $1,062,098,938
- % of total 13F portfolios
- 0%
- Share change
- +805,646
- Value change
- +$35,010,217
- Number of holders
- 195
- Price from insider filings
- $24.55
Reported Shares, Excluding Options vs Price
Reported Value, Excluding Options
Total Investors
Quick Takeaways
- CSTL - CASTLE BIOSCIENCES INC - Common Stock is tracked under CUSIP 14843C105.
- 195 institutions reported positions in Q4 2025.
- 5 significant owners is listed from Schedule 13D/13G reporting.
What Changed
- Holder count moved from 195 to 103 between Q4 2025 and Q1 2026.
- Reported value moved from $1,062,098,938 to $343,157,016.
Why This Matters
- You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
- 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.
Source Evidence
Source: SEC Form 13F
Open SEC Evidence
Latest holder context comes from 195 institutions filings for Q4 2025.
Investment Quick Answers
What is CUSIP 14843C105?
CUSIP 14843C105 identifies CSTL - CASTLE BIOSCIENCES INC - Common Stock in SEC 13F datasets.
Where can I see the latest institutional holders?
Review the Q4 2025 holders report and the ownership history table below.
Next ownership checks
Use the next link that matches the question you still need to answer about this security.
- Latest 13F filings when you want to inspect fresh institutional portfolio moves.
- Latest Schedule 13D/13G reports when you need large-owner changes outside the 13F cycle.
- All institutional ownership pages to compare this security with other holder-history pages.
Recent Quarterly Holder Reports
Open recent reporting periods for CUSIP 14843C105:
Significant Owners of CASTLE BIOSCIENCES INC - Common Stock (CSTL) based on Schedule 13D/G filings
| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| BlackRock, Inc. | 8.2% | $47,017,281 | 2,338,005 | BlackRock, Inc. | 31 Mar 2025 | |||
| RTW INVESTMENTS, LP | 7.2% | $84,757,547 | 2,115,237 | RTW Investments, LP | 31 Dec 2025 | |||
| Portolan Capital Management, LLC | 5.6% | $32,399,201 | 1,611,099 | Portolan Capital Management, LLC | 07 Apr 2025 | |||
| DIMENSIONAL FUND ADVISORS LP | 3.9% | -24% | $44,494,010 | -$12,848,347 | 1,143,799 | -22% | Dimensional Fund Advisors LP | 31 Dec 2025 |
| WASATCH ADVISORS LP | 3.5% | $20,078,930 | 998,455 | WASATCH ADVISORS LP | 31 Mar 2025 |
As of 31 Dec 2025, 195 institutional investors reported holding 27,312,139 shares of CASTLE BIOSCIENCES INC - Common Stock (CSTL). This represents 93% of the company’s total 29,378,292 outstanding shares.
Top 25 Institutional Shareholders
The largest institutional shareholders of CASTLE BIOSCIENCES INC - Common Stock (CSTL) together control 73% of the company’s outstanding shares — a level of ownership often associated with strong institutional conviction and long‑term capital commitment.
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| BlackRock, Inc. | 11% | 3,105,246 | -2.7% | 0% | $120,794,069 |
| VANGUARD GROUP INC | 7.5% | 2,199,829 | +1.3% | 0% | $85,573,349 |
| RTW INVESTMENTS, LP | 7.2% | 2,115,237 | 0.82% | $82,282,719 | |
| PRINCIPAL FINANCIAL GROUP INC | 6.2% | 1,807,644 | +0.74% | 0.04% | $70,317,352 |
| Portolan Capital Management, LLC | 5.9% | 1,729,463 | +14% | 3.6% | $67,276,111 |
| DIMENSIONAL FUND ADVISORS LP | 3.9% | 1,143,799 | -22% | 0.01% | $44,494,673 |
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC | 3.6% | 1,058,725 | +165% | 1.2% | $41,184,403 |
| STATE STREET CORP | 2.5% | 736,454 | +1.7% | 0% | $28,648,061 |
| GEODE CAPITAL MANAGEMENT, LLC | 2.4% | 714,913 | +2.3% | 0% | $27,814,871 |
| AIGH Capital Management LLC | 2.1% | 624,719 | -12% | 7.2% | $24,301,569 |
| Allianz Asset Management GmbH | 2.1% | 622,299 | -4% | 0.03% | $24,207,431 |
| PALISADE CAPITAL MANAGEMENT, LP | 1.9% | 567,777 | -11% | 0.65% | $22,086,525 |
| WASATCH ADVISORS LP | 1.8% | 537,241 | -20% | 0.12% | $20,898,675 |
| Nuveen, LLC | 1.8% | 524,681 | -45% | 0.01% | $20,410,091 |
| RENAISSANCE TECHNOLOGIES LLC | 1.7% | 493,100 | -12% | 0.03% | $19,181,590 |
| SCHRODER INVESTMENT MANAGEMENT GROUP | 1.7% | 492,161 | -0.56% | 0.01% | $19,346,849 |
| ACADIAN ASSET MANAGEMENT LLC | 1.3% | 390,406 | -14% | 0.02% | $15,180,000 |
| Connor, Clark & Lunn Investment Management Ltd. | 1.3% | 388,491 | +16% | 0.04% | $15,112,300 |
| CITADEL ADVISORS LLC | 1.2% | 366,356 | +46% | 0.01% | $14,251,249 |
| MILLENNIUM MANAGEMENT LLC | 1.1% | 308,914 | -46% | 0.01% | $12,016,755 |
| EVENTIDE ASSET MANAGEMENT, LLC | 1% | 305,000 | 0.19% | $11,864,500 | |
| GOLDMAN SACHS GROUP INC | 0.98% | 287,235 | -17% | 0% | $11,173,441 |
| KORNITZER CAPITAL MANAGEMENT INC /KS | 0.91% | 267,733 | -3.8% | 0.22% | $10,414,814 |
| BANK OF AMERICA CORP /DE/ | 0.9% | 263,019 | -17% | 0% | $10,231,439 |
| NORTHERN TRUST CORP | 0.89% | 262,243 | -7.1% | 0% | $10,201,253 |
Institutional Holders of CASTLE BIOSCIENCES INC - Common Stock (CSTL) across Reporting Periods
| Period | Reported Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q1 | 13,983,185 | $343,157,016 | -$10,019,683 | $24.55 | 103 |
| 2025 Q4 | 27,312,139 | $1,062,098,938 | +$35,010,217 | $38.90 | 195 |
| 2025 Q3 | 26,525,698 | $603,808,247 | +$704,267 | $22.77 | 170 |
| 2025 Q2 | 26,536,136 | $541,803,165 | +$16,367,707 | $20.42 | 151 |
| 2025 Q1 | 25,785,418 | $516,159,447 | -$22,608,207 | $20.02 | 180 |
| 2024 Q4 | 26,505,010 | $706,396,254 | +$8,987,296 | $26.65 | 197 |
| 2024 Q3 | 25,823,597 | $736,872,924 | +$15,687,154 | $28.52 | 185 |
| 2024 Q2 | 25,237,547 | $549,387,569 | +$5,246,303 | $21.77 | 158 |
| 2024 Q1 | 24,977,542 | $553,239,171 | +$24,692,740 | $22.15 | 148 |
| 2023 Q4 | 23,883,435 | $515,429,989 | +$17,867,692 | $21.58 | 150 |
| 2023 Q3 | 23,151,664 | $391,032,725 | +$7,780,165 | $16.89 | 133 |
| 2023 Q2 | 22,797,205 | $312,778,898 | -$3,698,099 | $13.72 | 128 |
| 2023 Q1 | 22,094,408 | $501,938,865 | +$5,568,015 | $22.72 | 148 |
| 2022 Q4 | 22,279,170 | $524,435,055 | +$5,715,957 | $23.54 | 152 |
| 2022 Q3 | 21,906,465 | $571,186,085 | -$14,799,148 | $26.08 | 152 |
| 2022 Q2 | 22,558,449 | $495,033,707 | -$115,268,932 | $21.95 | 141 |
| 2022 Q1 | 22,780,568 | $1,019,269,661 | +$62,738,499 | $44.86 | 153 |
| 2021 Q4 | 21,449,510 | $918,308,511 | -$59,908,643 | $42.87 | 153 |
| 2021 Q3 | 20,974,973 | $1,396,164,362 | +$40,585,506 | $66.50 | 182 |
| 2021 Q2 | 20,801,213 | $1,521,315,172 | -$4,483,937 | $73.33 | 176 |
| 2021 Q1 | 21,328,263 | $1,459,495,488 | +$90,506,347 | $68.46 | 173 |
| 2020 Q4 | 19,063,994 | $1,280,953,552 | +$376,683,100 | $67.15 | 160 |
| 2020 Q3 | 13,395,783 | $689,395,356 | +$88,062,594 | $51.45 | 144 |
| 2020 Q2 | 11,747,525 | $443,283,646 | +$169,050,988 | $37.69 | 125 |
| 2020 Q1 | 7,359,714 | $219,391,385 | +$66,312,670 | $29.81 | 88 |
| 2019 Q4 | 5,108,808 | $175,588,000 | +$15,879,309 | $34.37 | 66 |
| 2019 Q3 | 4,868,946 | $88,077,000 | +$69,427,000 | $18.09 | 56 |