Castle Biosciences Inc (CSTL) insider trading.
In Q3 2026, insiders at Castle Biosciences Inc reported 106 non-derivative transactions on 20 Forms 3, 4 and 5: 0 open-market purchases and 94 sales worth $7.9M.
- Transactions
- 106
- Purchases (P)
- 0
- Sales (S)
- 94
- Net shares, P minus S
- -256,597
- Insiders
- 4
- Last filed
- 2026-09-23
Insiders
| Insider | Relationship | Transactions | Buys | Sales |
|---|---|---|---|---|
| Maetzold Derek J | Director, Officer · Pres. & Chief Exec. Officer | 84 | 0 | 73 |
| Oelschlager Kristen M | Officer · Chief Operating Officer | 11 | 0 | 10 |
| Juvenal Tobin W | Officer · Chief Commercial Officer | 10 | 0 | 10 |
| Stokes Frank | Officer · Chief Financial Officer | 1 | 0 | 1 |
Transactions
| Date | Insider | Code | Shares | Price | Owned after | Filing |
|---|---|---|---|---|---|---|
| 2026-09-21 | Maetzold Derek J | S (D) | 2,718 | $35.33 | 9,550 | Form 4 |
| 2026-09-21 | Maetzold Derek J | S (D) | 3,198 | $35.33 | 11,236 | Form 4 |
| 2026-09-21 | Maetzold Derek J | M (A) | 8,580 | $2.39 | 30,059 | Form 4 |
| 2026-09-21 | Maetzold Derek J | S (D) | 8,580 | $35.33 | 21,479 | Form 4 |
| 2026-09-15 | Juvenal Tobin W | S (D) | 3,294 | $35.14 | 58,584 | Form 4 |
| 2026-09-14 | Juvenal Tobin W | S (D) | 3,306 | $32.32 | 61,878 | Form 4 |
| 2026-09-11 | Maetzold Derek J | M (A) | 8,584 | $2.39 | 30,063 | Form 4 |
| 2026-09-11 | Maetzold Derek J | S (D) | 8,361 | $32 | 21,702 | Form 4 |
| 2026-09-11 | Maetzold Derek J | S (D) | 3,124 | $32 | 14,517 | Form 4 |
| 2026-09-11 | Maetzold Derek J | S (D) | 2,656 | $32 | 12,339 | Form 4 |
| 2026-09-11 | Maetzold Derek J | S (D) | 71 | $32.78 | 12,268 | Form 4 |
| 2026-09-11 | Maetzold Derek J | S (D) | 83 | $32.78 | 14,434 | Form 4 |
| 2026-09-11 | Maetzold Derek J | S (D) | 223 | $32.78 | 21,479 | Form 4 |
| 2026-09-01 | Oelschlager Kristen M | S (D) | 200 | $34.02 | 13,356 | Form 4 |
| 2026-09-01 | Oelschlager Kristen M | S (D) | 3,952 | $33.36 | 13,556 | Form 4 |
| 2026-09-01 | Oelschlager Kristen M | M (A) | 4,152 | $3.38 | 17,508 | Form 4 |
| 2026-08-31 | Juvenal Tobin W | S (D) | 1,730 | $32.81 | 65,184 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 2,505 | $33.14 | 17,850 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 2,129 | $33.14 | 15,172 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 257 | $33.14 | 11,277 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 257 | $33.14 | 11,277 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 21 | $33.88 | 11,256 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 257 | $33.14 | 11,277 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 956 | $33.88 | 21,479 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 209 | $33.88 | 17,641 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 177 | $33.88 | 14,995 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 21 | $33.88 | 11,256 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 21 | $33.88 | 11,256 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 21 | $33.88 | 11,256 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 11,472 | $33.14 | 22,435 | Form 4 |
| 2026-08-28 | Maetzold Derek J | M (A) | 12,428 | $2.39 | 33,907 | Form 4 |
| 2026-08-28 | Maetzold Derek J | S (D) | 257 | $33.14 | 11,277 | Form 4 |
| 2026-08-25 | Juvenal Tobin W | S (D) | 9,050 | $35.04 | 66,914 | Form 4 |
| 2026-08-25 | Oelschlager Kristen M | S (D) | 7,161 | $34.26 | 77,872 | Form 4 |
| 2026-08-25 | Oelschlager Kristen M | S (D) | 5,223 | $34.64 | 72,649 | Form 4 |
| 2026-08-24 | Oelschlager Kristen M | S (D) | 12,218 | $33.69 | 85,033 | Form 4 |
| 2026-08-17 | Juvenal Tobin W | S (D) | 1,730 | $29.59 | 75,964 | Form 4 |
| 2026-08-14 | Maetzold Derek J | M (A) | 1,100 | $2.39 | 22,579 | Form 4 |
| 2026-08-14 | Maetzold Derek J | S (D) | 1,100 | $30.02 | 21,479 | Form 4 |
| 2026-08-14 | Maetzold Derek J | S (D) | 2,714 | $30.02 | 20,355 | Form 4 |
| 2026-08-14 | Maetzold Derek J | S (D) | 2,306 | $30.02 | 17,301 | Form 4 |
| 2026-08-14 | Maetzold Derek J | S (D) | 278 | $30.02 | 11,534 | Form 4 |
| 2026-08-14 | Maetzold Derek J | S (D) | 278 | $30.02 | 11,534 | Form 4 |
| 2026-08-14 | Maetzold Derek J | S (D) | 278 | $30.02 | 11,534 | Form 4 |
| 2026-08-14 | Maetzold Derek J | S (D) | 278 | $30.02 | 11,534 | Form 4 |
| 2026-08-14 | Stokes Frank | S (D) | 24,908 | $29.77 | 35,177 | Form 4 |
| 2026-08-05 | Maetzold Derek J | M (A) | 2,546 | $2.39 | 24,025 | Form 4 |
| 2026-08-05 | Maetzold Derek J | S (D) | 2,546 | $30.68 | 21,479 | Form 4 |
| 2026-08-05 | Maetzold Derek J | S (D) | 556 | $30.68 | 23,069 | Form 4 |
| 2026-08-05 | Maetzold Derek J | S (D) | 473 | $30.68 | 19,607 | Form 4 |
| 2026-08-04 | Maetzold Derek J | S (D) | 11,935 | $31.34 | 21,479 | Form 4 |
| 2026-08-04 | Maetzold Derek J | S (D) | 4,782 | $31.34 | 23,625 | Form 4 |
| 2026-08-04 | Maetzold Derek J | S (D) | 4,063 | $31.34 | 20,080 | Form 4 |
| 2026-08-04 | Maetzold Derek J | S (D) | 2,866 | $30.79 | 24,143 | Form 4 |
| 2026-08-04 | Maetzold Derek J | S (D) | 3,374 | $30.79 | 28,407 | Form 4 |
| 2026-08-04 | Maetzold Derek J | S (D) | 8,421 | $30.79 | 33,414 | Form 4 |
| 2026-08-04 | Maetzold Derek J | M (A) | 20,356 | $2.39 | 41,835 | Form 4 |
| 2026-08-03 | Oelschlager Kristen M | S (D) | 1,100 | $30.62 | 13,288 | Form 4 |
| 2026-08-03 | Oelschlager Kristen M | S (D) | 3,000 | $29.12 | 18,874 | Form 4 |
| 2026-08-03 | Oelschlager Kristen M | S (D) | 4,486 | $30 | 14,388 | Form 4 |
| 2026-08-03 | Maetzold Derek J | S (D) | 4,232 | $30.35 | 31,781 | Form 4 |
| 2026-08-03 | Maetzold Derek J | S (D) | 10,664 | $30.35 | 21,479 | Form 4 |
| 2026-08-03 | Maetzold Derek J | M (A) | 10,664 | $2.39 | 32,143 | Form 4 |
| 2026-08-03 | Maetzold Derek J | S (D) | 3,597 | $30.35 | 27,009 | Form 4 |
| 2026-08-03 | Juvenal Tobin W | S (D) | 1,730 | $28.25 | 78,995 | Form 4 |
| 2026-07-31 | Maetzold Derek J | S (D) | 1,690 | $30.15 | 30,606 | Form 4 |
| 2026-07-31 | Maetzold Derek J | M (A) | 6,480 | $2.39 | 27,959 | Form 4 |
| 2026-07-31 | Maetzold Derek J | S (D) | 6,480 | $30.15 | 21,479 | Form 4 |
| 2026-07-31 | Maetzold Derek J | S (D) | 1,983 | $30.15 | 36,013 | Form 4 |
| 2026-07-31 | Juvenal Tobin W | S (D) | 1,891 | $30.26 | 80,725 | Form 4 |
| 2026-07-31 | Juvenal Tobin W | S (D) | 8,149 | $28.84 | 89,886 | Form 4 |
| 2026-07-31 | Juvenal Tobin W | S (D) | 7,270 | $29.58 | 82,616 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 43 | $25.06 | 32,296 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 10 | $25.06 | 11,812 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 10 | $25.06 | 11,812 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 10 | $25.06 | 11,812 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 10 | $25.06 | 11,812 | Form 4 |
| 2026-07-27 | Maetzold Derek J | M (A) | 6,214 | $2.39 | 27,693 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 5,982 | $24.13 | 21,711 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 1,307 | $24.13 | 38,046 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 1,110 | $24.13 | 32,339 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 268 | $24.13 | 11,822 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 268 | $24.13 | 11,822 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 268 | $24.13 | 11,822 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 268 | $24.13 | 11,822 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 232 | $25.06 | 21,479 | Form 4 |
| 2026-07-27 | Maetzold Derek J | S (D) | 50 | $25.06 | 37,996 | Form 4 |
| 2026-07-14 | Maetzold Derek J | M (A) | 550 | $2.39 | 22,029 | Form 4 |
| 2026-07-14 | Maetzold Derek J | S (D) | 550 | $22.92 | 21,479 | Form 4 |
| 2026-07-14 | Maetzold Derek J | S (D) | 1,357 | $22.92 | 39,353 | Form 4 |
| 2026-07-14 | Maetzold Derek J | S (D) | 278 | $22.92 | 12,090 | Form 4 |
| 2026-07-14 | Maetzold Derek J | S (D) | 278 | $22.92 | 12,090 | Form 4 |
| 2026-07-14 | Maetzold Derek J | S (D) | 278 | $22.92 | 12,090 | Form 4 |
| 2026-07-14 | Maetzold Derek J | S (D) | 278 | $22.92 | 12,090 | Form 4 |
| 2026-07-14 | Maetzold Derek J | S (D) | 1,153 | $22.92 | 33,449 | Form 4 |
| 2026-07-01 | Oelschlager Kristen M | S (D) | 8,186 | $24.4 | 22,274 | Form 4 |
| 2026-07-01 | Oelschlager Kristen M | S (D) | 400 | $24.78 | 21,874 | Form 4 |
| 2026-07-01 | Maetzold Derek J | S (D) | 1,357 | $24.29 | 40,710 | Form 4 |
| 2026-07-01 | Maetzold Derek J | S (D) | 1,153 | $24.29 | 34,602 | Form 4 |
| 2026-07-01 | Maetzold Derek J | S (D) | 278 | $24.29 | 12,368 | Form 4 |
| 2026-07-01 | Maetzold Derek J | S (D) | 6,214 | $24.29 | 21,479 | Form 4 |
| 2026-07-01 | Maetzold Derek J | M (A) | 6,214 | $2.39 | 27,693 | Form 4 |
| 2026-07-01 | Maetzold Derek J | S (D) | 278 | $24.29 | 12,368 | Form 4 |
| 2026-07-01 | Maetzold Derek J | S (D) | 278 | $24.29 | 12,368 | Form 4 |
| 2026-07-01 | Maetzold Derek J | S (D) | 278 | $24.29 | 12,368 | Form 4 |
| 2025-11-24 | Juvenal Tobin W | S (D) | 1,301 | $38.39 | 77,694 | Form 4 |
Transaction codes in this quarter
Get CSTL insider transactions through the API
Request with your API key
curl "https://sec-api.dev/api/v1/insider-transactions?period=2026q3&cik=1447362&limit=100" \
-H "Authorization: Bearer $SEC_API_KEY"Insider trading API guide · CSTL company page · Castle Biosciences Inc on SEC.gov
Questions
Are insiders buying or selling Castle Biosciences Inc (CSTL)?
In Q3 2026, insiders at Castle Biosciences Inc reported 106 non-derivative transactions on 20 Forms 3, 4 and 5: 0 open-market purchases and 94 sales worth $7.9M. Grants, tax withholding and option exercises are counted as transactions but are not purchases or sales.
Where do these Castle Biosciences Inc insider trades come from?
From the SEC Insider Transactions Data Sets for Q3 2026, which republish the Forms 3, 4 and 5 filed on EDGAR. Each row links to its filing on SEC.gov.
Source: SEC Insider Transactions Data Sets, Q3 2026, retrieved 2026-10-27. Footnotes, derivative holdings and amendments are in the linked filings. Not investment advice.
Plain-text version for agents and LLMs: /insider-trading/cstl.md
Independent. Not affiliated with, endorsed by, or sponsored by the U.S. Securities and Exchange Commission. Data is reproduced from public SEC filings and datasets. Not investment advice.