Form4insider filings, from the source

Company · CIK 0001447362 · SIC 8071 — Services-Medical Laboratories · Nasdaq

CASTLE BIOSCIENCES INC · CSTL

Insider activity reported against this company. All insider holders · On EDGAR ↗

1M3M6M1Y2YAll datashares as filed — not split-adjusted
Open-market buys & salesbuys $0 · 0sales $8.4M · 23net −$8.4M
$10k$10k$100k$100k$1M$1M$10M$10MbuyssalesNov 23Jan 12Mar 4Apr 23Jun 13Aug 2Sep 22

Reported at this company — common stock

TradeReported (ET)InsiderSharesAvg priceTotalOwned afterΔ stakeFlags
Sep 21, 2026 SForm 4 →Sep 23, 4:27 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director14,496$35.33$512,2029,550−60.3%10b5-1
Sep 21, 2026 MForm 4 →Sep 23, 4:27 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director8,580$2.39$20,50630,059—10b5-1
Sep 14, 2026 SForm 4 →Sep 16, 4:20 pm EDTTobin W JuvenalChief Commercial Officer6,600$33.73$222,62158,584−10.1%10b5-1
Sep 11, 2026 SForm 4 →Sep 15, 4:08 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director14,518$32.02$464,87012,268−54.2%10b5-1
Sep 11, 2026 MForm 4 →Sep 15, 4:08 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director8,584$2.39$20,51630,063—10b5-1
Sep 1, 2026 SForm 4 →Sep 3, 4:07 pm EDTKristen M OelschlagerChief Operating Officer4,152$33.39$138,64313,356−23.7%10b5-1
Sep 1, 2026 MForm 4 →Sep 3, 4:07 pm EDTKristen M OelschlagerChief Operating Officer4,152$3.38$14,03417,508—10b5-1
Aug 31, 2026 SForm 4 →Sep 2, 4:07 pm EDTTobin W JuvenalChief Commercial Officer1,730$32.81$56,76165,184−2.59%10b5-1
Aug 28, 2026 SForm 4 →Sep 1, 4:12 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director18,560$33.20$616,13411,256−62.2%10b5-1
Aug 28, 2026 MForm 4 →Sep 1, 4:12 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director12,428$2.39$29,70333,907—10b5-1
Aug 25, 2026 SForm 4 →Aug 27, 4:38 pm EDTTobin W JuvenalChief Commercial Officer9,050$35.04$317,11266,914−11.9%10b5-1
Aug 24, 2026 SForm 4 →Aug 26, 4:16 pm EDTKristen M OelschlagerChief Operating Officer24,602$34.06$837,86572,649−25.3%
Aug 17, 2026 SForm 4 →Aug 19, 4:11 pm EDTTobin W JuvenalChief Commercial Officer1,730$29.59$51,19175,964−2.23%10b5-1
Aug 14, 2026 SForm 4 →Aug 18, 4:10 pm EDTFrank StokesChief Financial Officer24,908$29.77$741,51135,177−41.5%
Aug 14, 2026 SForm 4 →Aug 18, 4:09 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director7,232$30.02$217,10511,534−38.5%10b5-1
Aug 14, 2026 MForm 4 →Aug 18, 4:09 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director1,100$2.39$2,62922,579—10b5-1
Aug 4, 2026 SForm 4 →Aug 6, 4:14 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director39,016$31.07$1,212,23019,607−66.6%10b5-1
Aug 4, 2026 MForm 4 →Aug 6, 4:14 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director22,902$2.39$54,73624,025—10b5-1
Aug 3, 2026 SForm 4 →Aug 5, 4:18 pm EDTKristen M OelschlagerChief Operating Officer8,586$29.77$255,62213,288−39.3%10b5-1
Jul 31, 2026 SForm 4 →Aug 4, 4:36 pm EDTTobin W JuvenalChief Commercial Officer19,040$29.21$556,17578,995−19.4%10b5-1
Jul 31, 2026 SForm 4 →Aug 4, 4:35 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director28,646$30.28$867,45127,009−51.5%10b5-1
Jul 31, 2026 MForm 4 →Aug 4, 4:35 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director17,144$2.39$40,97432,143—10b5-1
Jul 27, 2026 SForm 4 →Jul 29, 4:09 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director9,836$24.16$237,68211,812−45.4%10b5-1
Jul 27, 2026 MForm 4 →Jul 29, 4:09 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director6,214$2.39$14,85127,693—10b5-1
Jul 14, 2026 SForm 4 →Jul 16, 4:16 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director4,172$22.92$95,62212,090−25.7%10b5-1
Jul 14, 2026 MForm 4 →Jul 16, 4:16 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director550$2.39$1,31522,029—10b5-1
Jul 1, 2026 SForm 4 →Jul 6, 4:25 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director9,836$24.29$238,91612,368−44.3%10b5-1
Jul 1, 2026 MForm 4 →Jul 6, 4:25 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director6,214$2.39$14,85127,693—10b5-1
Jul 1, 2026 SForm 4 →Jul 6, 4:24 pm EDTKristen M OelschlagerChief Operating Officer8,586$24.42$209,65021,874−28.2%10b5-1
Jun 16, 2026 SForm 4 →Jun 18, 4:19 pm EDTKristen M OelschlagerChief Operating Officer8,587$20.71$177,83730,460−22.0%10b5-1
Jun 15, 2026 SForm 4 →Jun 17, 5:39 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director4,172$20.66$86,19412,646−24.8%10b5-1
Jun 15, 2026 MForm 4 →Jun 17, 5:39 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director550$2.39$1,31522,029—10b5-1
Jun 1, 2026 SForm 4 →Jun 3, 4:15 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director9,836$20.86$205,1491,668−85.5%10b5-1
Jun 1, 2026 MForm 4 →Jun 3, 4:15 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director6,214$2.39$14,85127,693—10b5-1
Nov 24, 2025 SForm 4 →Aug 6, 2026, 4:14 pm EDTTobin W JuvenalChief Commercial Officer1,301$38.39$49,94577,694−1.65%10b5-1 late

Reported at this company — derivatives (options, RSUs, warrants)

TradeReported (ET)InsiderSharesAvg priceTotalOwned afterΔ stakeFlags
Sep 21, 2026 MForm 4 →Sep 23, 4:27 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director8,580——8,165—10b5-1
Sep 11, 2026 MForm 4 →Sep 15, 4:08 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director8,584——16,745—10b5-1
Sep 1, 2026 MForm 4 →Sep 3, 4:07 pm EDTKristen M OelschlagerChief Operating Officer4,152——12,458—10b5-1
Aug 28, 2026 MForm 4 →Sep 1, 4:12 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director12,428——25,329—10b5-1
Aug 14, 2026 MForm 4 →Aug 18, 4:09 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director1,100——37,757—10b5-1
Aug 4, 2026 MForm 4 →Aug 6, 4:14 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director22,902——38,857—10b5-1
Jul 31, 2026 MForm 4 →Aug 4, 4:35 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director17,144——61,759—10b5-1
Jul 27, 2026 MForm 4 →Jul 29, 4:09 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director6,214——78,903—10b5-1
Jul 14, 2026 MForm 4 →Jul 16, 4:16 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director550——85,117—10b5-1
Jul 1, 2026 MForm 4 →Jul 6, 4:25 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director6,214——85,667—10b5-1
Jun 15, 2026 MForm 4 →Jun 17, 5:39 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director550——91,881—10b5-1
Jun 1, 2026 MForm 4 →Jun 3, 4:15 pm EDTDerek J MaetzoldPres. & Chief Exec. Officer, Director6,214——92,431—10b5-1