Castle Biosciences Inc
CSTL- Exchange
- Nasdaq
- Industry
- Services-Medical Laboratories
- SEC CIK
- 0001447362
In the last 90 days, Castle Biosciences Inc insiders filed 0 open-market purchases and 20 sales; 176 institutions reported holding it in 13F filings for Q2 2026, worth $653.8M in total; no superinvestor holds it.
Holders of 5% or more of CSTL
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Castle Biosciences Inc, largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| RTW Investments, LP | 13G/A | 9.30%2.76M shares | +2.10 ppfrom 7.20% | Feb 17, 20262 filings | May 15, 2026 | SEC |
| BlackRock, Inc. | 13G/A | 8.20%2.34M shares | – | Apr 23, 20251 filing | Apr 23, 2025 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
32 Schedule 13D and 13G filings on Castle Biosciences Inc, newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Oct 29, 202610:32 AM ET | Principal Global Investors | 13G/A | 4.90%1.50M shares | –Below 5% | Sep 30, 2026 | SEC |
| May 15, 20264:10 PM ET | Portolan Capital Management, LLCand 1 other | 13G/A | 4.45%1.35M shares | −1.20 ppfrom 5.65%Below 5% | Mar 31, 2026 | SEC |
| May 15, 20268:10 AM ET | RTW Investments, LPand 1 other | 13G/A | 9.30%2.76M shares | +2.10 ppfrom 7.20% | Mar 31, 2026 | SEC |
| Mar 26, 20264:42 PM ET | Vanguard Group Inc | 13G/A | 0.00%0 shares | −6.54 ppfrom 6.54%Below 5% | Mar 13, 2026 | SEC |
| Feb 17, 20268:31 AM ET | RTW Investments, LPand 1 other | 13G | 7.20%2.12M shares | New | Dec 31, 2025 | SEC |
| Jan 21, 20261:21 PM ET | Dimensional Fund Advisors LP | 13G/A | 3.90%1.14M shares | −1.20 ppfrom 5.10%Below 5% | Dec 31, 2025 | SEC |
| Oct 9, 20251:48 PM ET | Dimensional Fund Advisors LP | 13G | 5.10%1.47M shares | New | Sep 30, 2025 | SEC |
| May 12, 20253:55 PM ET | Wasatch Advisors Inc | 13G/A | 3.50%998.5K shares | –Below 5% | Mar 31, 2025 | SEC |
| Apr 23, 20258:19 PM ET | BlackRock, Inc. | 13G/A | 8.20%2.34M shares | – | Mar 31, 2025 | SEC |
| Apr 14, 20253:34 PM ET | Portolan Capital Management, LLCand 1 other | 13G | 5.65%1.61M shares | New | Apr 7, 2025 | SEC |
| Jan 30, 20259:33 PM ET | Vanguard Group Inc | 13G/A | 6.54%1.83M shares | – | Dec 31, 2024 | SEC |
| Nov 14, 2024 | Granahan Investment Management Inc | 13G/AOld format | – | – | – | SEC |
| Nov 13, 2024 | Wasatch Advisors Inc | 13G/AOld format | – | – | – | SEC |
| Jul 8, 20244:32 PM ET | BlackRock Inc. | 13G/AOld format | – | – | – | SEC |
| Feb 14, 2024 | Granahan Investment Management Inc | 13GOld format | – | New | – | SEC |
| Feb 13, 2024 | Principal Global Investors | 13GOld format | – | New | – | SEC |
| Feb 13, 2024 | Vanguard Group Inc | 13G/AOld format | – | – | – | SEC |
| Feb 9, 2024 | Wasatch Advisors Inc | 13G/AOld format | – | – | – | SEC |
| Jan 25, 20241:48 PM ET | BlackRock Inc. | 13G/AOld format | – | – | – | SEC |
| Feb 9, 2023 | Vanguard Group Inc | 13GOld format | – | New | – | SEC |
| Feb 9, 2023 | Wasatch Advisors Inc | 13G/AOld format | – | – | – | SEC |
| Feb 3, 20234:27 PM ET | BlackRock Inc. | 13G/AOld format | – | – | – | SEC |
| Feb 11, 2022 | Maetzold Derek J | 13G/AOld format | – | – | – | SEC |
| Feb 10, 2022 | Wasatch Advisors Inc | 13G/AOld format | – | – | – | SEC |
| Feb 4, 20224:12 PM ET | BlackRock Inc. | 13GOld format | – | New | – | SEC |
| Jun 10, 2021 | Wasatch Advisors Inc | 13G/AOld format | – | – | – | SEC |
| Feb 17, 2021 | Bradbury Daniel | 13G/AOld format | – | – | – | SEC |
| Feb 17, 2021 | Maetzold Derek J | 13G/AOld format | – | – | – | SEC |
| Feb 16, 2021 | MGC Venture Partners 2013 GP, LLC | 13G/AOld format | – | – | – | SEC |
| Feb 12, 2021 | Industry Ventures Healthcare, LLC | 13G/AOld format | – | – | – | SEC |
| Feb 11, 2021 | Wasatch Advisors Inc | 13GOld format | – | New | – | SEC |
| Feb 10, 2021 | ARK Investment Management LLCSuperinvestorARK Invest | 13GOld format | – | New | – | SEC |
Form 144: proposed insider sales
71 notices from officers, directors and other affiliates planning to sell Castle Biosciences Inc shares, newest first.
| Filed (ET) | Seller | Shares to sell | Market value | Planned sale | Broker | Filing |
|---|---|---|---|---|---|---|
| Nov 12, 20268:30 AM ET | Tobin JuvenalOfficer | 3.19K | $112.0K | Nov 11, 2026 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Nov 9, 20266:37 PM ET | Tobin JuvenalChief Commercial Officer | 13.2K | $452.2K | Nov 9, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Nov 2, 20265:28 PM ET | Derek MaetzoldOfficer | 21.4K | $749.0K | Nov 2, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Oct 13, 20268:52 AM ET | Tobin JuvenalChief Commercial Officer | 13.2K | $430.9K | Oct 12, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Oct 5, 20266:24 PM ET | Derek MaetzoldOfficer | 29.0K | $1.06M | Oct 5, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Oct 1, 20264:24 PM ET | Kristen OelschlagerOfficer | 4.15K | $147.6K | Oct 1, 202610b5-1 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Sep 14, 20266:00 PM ET | Tobin JuvenalChief Commercial Officer | 13.2K | $440.6K | Sep 14, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Sep 11, 20266:53 PM ET | Derek MaetzoldOfficer | 29.0K | $938.0K | Sep 11, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Aug 25, 20265:46 PM ET | Tobin JuvenalChief Commercial Officer | 22.5K | $787.5K | Aug 25, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Aug 24, 20264:47 PM ET | Kristen M. OelschlagerOfficer | 24.6K | $841.4K | Aug 24, 2026 | J.P. Morgan Securities LLC | SEC |
| Aug 14, 20266:50 PM ET | Franklin M. StokesOfficer | 24.9K | $741.5K | Aug 14, 2026 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Aug 14, 20265:38 PM ET | Derek MaetzoldOfficer | 25.8K | $764.0K | Aug 14, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Jul 31, 20264:52 PM ET | Tobin JuvenalChief Commercial Officer | 22.5K | $630.0K | Jul 31, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Jul 31, 20264:52 PM ET | Derek MaetzoldOfficer | 67.7K | $1.89M | Jul 31, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Jul 1, 20265:35 PM ET | Derek MaetzoldOfficer | 23.8K | $589.2K | Jul 1, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Jun 16, 20264:35 PM ET | Kristen OelschlagerOfficer | 29.9K | $618.0K | Jun 16, 202610b5-1 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Jun 1, 20265:39 PM ET | Derek MaetzoldOfficer | 14.0K | $293.7K | Jun 1, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| May 7, 20264:56 PM ET | Derek MaetzoldOfficer | 14.0K | $269.5K | May 7, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Mar 26, 20265:36 PM ET | Derek MaetzoldOfficer | 18.2K | $449.0K | Mar 26, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Mar 12, 20264:38 PM ET | Tobin JuvenalChief Commercial Officer | 20.9K | $528.3K | Mar 12, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Mar 11, 20264:52 PM ET | Derek MaetzoldOfficer | 94.2K | $2.46M | Mar 11, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
| Mar 5, 20264:28 PM ET | Franklin StokesOfficer | 6.00K | $169.0K | Mar 5, 202610b5-1 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Mar 5, 20264:04 PM ET | Gordon B. ColeDirector | 7.40K | $210.7K | Mar 5, 2026 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Mar 3, 20264:33 PM ET | Franklin StokesOfficer | 7.00K | $195.9K | Mar 3, 202610b5-1 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Jan 5, 20265:09 PM ET | Derek MaetzoldOfficer | 12.1K | $470.0K | Jan 5, 202610b5-1 | Goldman Sachs & Co. LLC | SEC |
Showing the latest 25. See the CSTL notices from the last 12 months