CASTLE BIOSCIENCES INC (CSTL)
Institutional ownership reported to the SEC as of Q3 2026, across 29 quarters.
Calls and puts are the parts of reported value carried in derivative lines rather than shares, and they point in opposite directions: a manager holding calls is positioned for the security, one holding puts against it - or hedging shares they already own, which is why index funds carry so many. Most sites add the two together and report one figure, which averages away the only interesting part.
Holders
| Filer | Value | Shares | Their book | Held | Change |
|---|---|---|---|---|---|
| Green Alpha Advisors, LLC | $491.3K | 13,828 | 0.33% | 5q | +39.1%+$138.1K |
| Farther Finance Advisors, LLC | $58.0K | 1,632 | 0.00% | 12q | -9.6%-$6.2K |
| GK Wealth Management LLC | $7.6K | 214 | 0.00% | new | NEW |
| Versant Capital Management, Inc | $5.5K | 154 | 0.00% | 6q | +22.2% |
| GAMMA Investing LLC | $782 | 22 | 0.00% | 12q | +15.8% |
What the insiders did
Open market purchases and sales reported on Form 4 in the last 180 days. Grants, option exercises and shares surrendered to cover tax are left out: they are compensation rather than a decision to buy or sell. Where a broker filled one order in tranches the lines are summed, because it was one decision.
Officers and directors
| Date | Insider | Role | Side | Shares | Value |
|---|---|---|---|---|---|
| 2026-08-04 | MAETZOLD DEREK J | Pres. & Chief Exec. Officer | Sold | 35,441 | $1.1M ×6 |
| 2026-08-14 | Stokes Frank | Chief Financial Officer | Sold | 24,908 | $741.5K |
| 2026-08-28 | MAETZOLD DEREK J | Pres. & Chief Exec. Officer | Sold | 18,560 | $616.1K ×14 |
| 2026-08-03 | MAETZOLD DEREK J | Pres. & Chief Exec. Officer | Sold | 18,493 | $561.3K ×3 |
| 2026-10-05 | MAETZOLD DEREK J | Pres. & Chief Exec. Officer | Sold | 14,496 | $515.6K ×3 |
| 2026-09-21 | MAETZOLD DEREK J | Pres. & Chief Exec. Officer | Sold | 14,496 | $512.2K ×3 |
| 2026-07-31 | Juvenal Tobin W | Chief Commercial Officer | Sold | 17,310 | $507.3K ×3 |
| 2026-09-11 | MAETZOLD DEREK J | Pres. & Chief Exec. Officer | Sold | 14,518 | $464.9K ×6 |
| 2026-08-25 | Oelschlager Kristen M | Chief Operating Officer | Sold | 12,384 | $426.3K ×2 |
| 2026-08-24 | Oelschlager Kristen M | Chief Operating Officer | Sold | 12,218 | $411.6K |
| 2026-07-31 | MAETZOLD DEREK J | Pres. & Chief Exec. Officer | Sold | 10,153 | $306.1K ×3 |
| 2026-08-03 | Oelschlager Kristen M | Chief Operating Officer | Sold | 8,586 | $255.6K ×3 |
Quarter by quarter
Coverage begins with the quarter ending 2018-12-31. Earlier filings exist only as occasional late amendments, too sparse to describe a market, so they are not shown.
| Quarter | Holders | Value | Shares | New | Added | Trimmed | Options |
|---|---|---|---|---|---|---|---|
| Q3 2026 | 5 | $563.2K | 15,850 | 1 | 3 | 1 | 0.0% |
| Q2 2026 | 180 | $706.7M | 29,598,710 | 24 | 77 | 53 | 0.0% |
| Q1 2026 | 188 | $681.3M | 27,659,023 | 24 | 71 | 54 | 0.3% |
| Q4 2025 | 198 | $1.1B | 27,348,638 | 40 | 63 | 66 | 0.3% |
| Q3 2025 | 173 | $611.5M | 26,734,423 | 37 | 59 | 51 | 0.2% |
| Q2 2025 | 154 | $546.3M | 26,753,805 | 15 | 66 | 44 | 0.0% |
| Q1 2025 | 180 | $520.6M | 26,046,004 | 28 | 72 | 52 | 0.1% |
| Q4 2024 | 200 | $718.6M | 26,774,541 | 34 | 61 | 66 | 0.7% |
| Q3 2024 | 187 | $753.7M | 26,048,581 | 44 | 73 | 48 | 1.4% |
| Q2 2024 | 160 | $567.8M | 25,394,776 | 29 | 52 | 47 | 2.6% |
| Q1 2024 | 151 | $592.9M | 26,480,973 | 16 | 54 | 52 | 1.1% |
| Q4 2023 | 152 | $529.9M | 24,545,406 | 31 | 53 | 42 | 0.0% |
| Q3 2023 | 135 | $393.6M | 23,218,962 | 20 | 49 | 39 | 0.4% |
| Q2 2023 | 131 | $318.6M | 23,039,263 | 18 | 68 | 25 | 0.3% |
| Q1 2023 | 147 | $505.0M | 22,198,111 | 14 | 59 | 33 | 0.1% |
| Q4 2022 | 154 | $524.2M | 22,222,909 | 23 | 47 | 53 | 0.2% |
| Q3 2022 | 157 | $575.7M | 21,856,966 | 25 | 54 | 46 | 1.0% |
| Q2 2022 | 145 | $495.7M | 22,558,806 | 25 | 69 | 27 | 0.1% |
| Q1 2022 | 160 | $1.0B | 22,807,071 | 22 | 65 | 42 | 0.0% |
| Q4 2021 | 157 | $920.1M | 21,464,597 | 15 | 61 | 47 | 0.1% |
| Q3 2021 | 187 | $1.4B | 21,502,992 | 20 | 76 | 49 | 0.2% |
| Q2 2021 | 181 | $1.5B | 20,801,687 | 37 | 74 | 39 | 0.6% |
| Q1 2021 | 176 | $1.5B | 21,328,706 | 33 | 70 | 55 | 1.0% |
| Q4 2020 | 167 | $1.3B | 20,005,701 | 37 | 63 | 45 | 1.0% |
| Q3 2020 | 145 | $693.0M | 13,451,323 | 29 | 63 | 35 | 0.1% |
| Q2 2020 | 125 | $444.2M | 11,763,039 | 46 | 50 | 18 | 0.1% |
| Q1 2020 | 88 | $220.5M | 7,398,227 | 31 | 36 | 14 | 0.0% |
| Q4 2019 | 66 | $177.6M | 5,167,588 | 20 | 28 | 12 | 0.0% |
| Q3 2019 | 57 | $88.1M | 4,869,109 | 56 | 0 | 0 | 0.0% |