CSTL
Castle Biosciences Inc
NASDAQ: CSTL · HEALTHCARE · DIAGNOSTICS & RESEARCH
$30.40
-2.50% today
Updated 2026-08-05
Market cap
$928.40M
P/E ratio
—
P/S ratio
2.60x
EPS (TTM)
$-0.64
Dividend yield
—
52W range
$18 – $44
Volume
0.4M
Castle Biosciences Inc (CSTL) Insider transactions
Net insider activity
Net selling (103,668 shares)
Buy transactions
22
Sell transactions
78
All transactions
| Date | Insider | Title | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| 2026-07-14 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 550 | — | — |
| 2026-07-14 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,357 | $22.92 | $31102.44 |
| 2026-07-14 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,153 | $22.92 | $26426.76 |
| 2026-07-14 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Buy | 550 | $2.39 | $1314.50 |
| 2026-07-14 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 278 | $22.92 | $6371.76 |
| 2026-07-01 | OELSCHLAGER, KRISTEN M | Chief Operating Officer | Sale | 8,186 | $24.40 | $199738.40 |
| 2026-07-01 | OELSCHLAGER, KRISTEN M | Chief Operating Officer | Sale | 400 | $24.78 | $9912.00 |
| 2026-07-01 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 6,214 | — | — |
| 2026-07-01 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Buy | 6,214 | $2.39 | $14851.46 |
| 2026-07-01 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,357 | $24.29 | $32961.53 |
| 2026-07-01 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,153 | $24.29 | $28006.37 |
| 2026-07-01 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 278 | $24.29 | $6752.62 |
| 2026-06-16 | OELSCHLAGER, KRISTEN M | Chief Operating Officer | Sale | 8,587 | $20.71 | $177836.77 |
| 2026-06-15 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 550 | — | — |
| 2026-06-15 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,357 | $20.66 | $28035.62 |
| 2026-06-15 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,153 | $20.66 | $23820.98 |
| 2026-06-15 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 550 | $20.66 | $11363.00 |
| 2026-06-15 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 278 | $20.66 | $5743.48 |
| 2026-06-01 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 6,010 | — | — |
| 2026-06-01 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 204 | — | — |
| 2026-06-01 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 6,214 | $20.86 | $129605.40 |
| 2026-06-01 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Buy | 6,010 | $2.39 | $14363.90 |
| 2026-06-01 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,357 | $20.86 | $28302.95 |
| 2026-06-01 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,153 | $20.86 | $24048.12 |
| 2026-06-01 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 278 | $20.86 | $5798.25 |
| 2026-06-01 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Buy | 204 | $2.39 | $487.56 |
| 2026-05-28 | OLSON, TIFFANY | Director | Buy | 11,766 | — | — |
| 2026-05-28 | HARRISON, MILES | Director | Buy | 11,766 | — | — |
| 2026-05-28 | GOLDBERG, ELLEN | Director | Buy | 11,766 | — | — |
| 2026-05-28 | COTTON, RODNEY | Director | Buy | 11,766 | — | — |
| 2026-05-28 | COLE, G BRADLEY | Director | Buy | 11,766 | — | — |
| 2026-05-28 | CAPLE, KIM | Director | Buy | 11,766 | — | — |
| 2026-05-28 | BRADBURY, DANIEL | Director | Buy | 11,766 | — | — |
| 2026-05-22 | OLSON, TIFFANY | Director | Sale | 13,667 | — | — |
| 2026-05-22 | OLSON, TIFFANY | Director | Buy | 13,667 | — | — |
| 2026-05-22 | HARRISON, MILES | Director | Sale | 13,667 | — | — |
| 2026-05-22 | HARRISON, MILES | Director | Buy | 13,667 | — | — |
| 2026-05-22 | GOLDBERG, ELLEN | Director | Sale | 13,667 | — | — |
| 2026-05-22 | GOLDBERG, ELLEN | Director | Buy | 13,667 | — | — |
| 2026-05-22 | COTTON, RODNEY | Director | Sale | 13,667 | — | — |
| 2026-05-22 | COTTON, RODNEY | Director | Buy | 13,667 | — | — |
| 2026-05-22 | COLE, G BRADLEY | Director | Sale | 13,667 | — | — |
| 2026-05-22 | COLE, G BRADLEY | Director | Buy | 13,667 | — | — |
| 2026-05-22 | CAPLE, KIM | Director | Sale | 13,667 | — | — |
| 2026-05-22 | CAPLE, KIM | Director | Buy | 13,667 | — | — |
| 2026-05-22 | BRADBURY, DANIEL | Director | Sale | 13,667 | — | — |
| 2026-05-22 | BRADBURY, DANIEL | Director | Buy | 13,667 | — | — |
| 2026-05-21 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 420 | — | — |
| 2026-05-21 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,035 | $20.20 | $20902.86 |
| 2026-05-21 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 880 | $20.20 | $17772.48 |
| 2026-05-21 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 420 | $20.20 | $8482.32 |
| 2026-05-21 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 212 | $20.20 | $4281.55 |
| 2026-05-21 | JUVENAL, TOBIN W | Chief Commercial Officer | Sale | 11,210 | — | — |
| 2026-05-21 | JUVENAL, TOBIN W | Chief Commercial Officer | Buy | 11,210 | $3.38 | $37889.80 |
| 2026-05-20 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 130 | — | — |
| 2026-05-20 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 322 | $20.00 | $6440.64 |
| 2026-05-20 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 273 | $20.00 | $5460.55 |
| 2026-05-20 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 130 | $20.00 | $2600.26 |
| 2026-05-20 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 66 | $20.00 | $1320.13 |
| 2026-05-07 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 6,214 | — | — |
| 2026-05-07 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Buy | 6,214 | $2.39 | $14851.46 |
| 2026-05-07 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 5,308 | $22.08 | $117200.64 |
| 2026-05-07 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,159 | $22.08 | $25590.72 |
| 2026-05-07 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 985 | $22.08 | $21748.80 |
| 2026-05-07 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 906 | $22.59 | $20462.01 |
| 2026-05-07 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 237 | $22.08 | $5232.96 |
| 2026-05-07 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 198 | $22.59 | $4471.83 |
| 2026-05-07 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 168 | $22.59 | $3794.28 |
| 2026-05-07 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 41 | $22.59 | $925.99 |
| 2026-04-21 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 550 | — | — |
| 2026-04-21 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,357 | $25.10 | $34057.99 |
| 2026-04-21 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,153 | $25.10 | $28937.99 |
| 2026-04-21 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 550 | $25.10 | $13803.90 |
| 2026-04-21 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 278 | $25.10 | $6977.24 |
| 2026-04-06 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 6,214 | — | — |
| 2026-04-06 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 6,214 | $25.03 | $155536.42 |
| 2026-04-06 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,357 | $25.03 | $33965.71 |
| 2026-04-06 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,153 | $25.03 | $28859.59 |
| 2026-04-06 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 278 | $25.03 | $6958.34 |
| 2026-03-26 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 550 | — | — |
| 2026-03-26 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,357 | $25.55 | $34672.71 |
| 2026-03-26 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,153 | $25.55 | $29460.30 |
| 2026-03-26 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 550 | $25.55 | $14053.05 |
| 2026-03-26 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 278 | $25.55 | $7103.18 |
| 2026-03-26 | COTTON, RODNEY | Director | Sale | 5,329 | — | — |
| 2026-03-26 | COTTON, RODNEY | Director | Buy | 5,329 | — | — |
| 2026-03-18 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 650 | $25.39 | $16503.50 |
| 2026-03-17 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 18,650 | $25.93 | $483594.50 |
| 2026-03-16 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 17,449 | $25.96 | $453045.84 |
| 2026-03-16 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 126 | $26.68 | $3361.68 |
| 2026-03-13 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 13,204 | $25.45 | $336002.19 |
| 2026-03-12 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 23,179 | $25.28 | $585941.94 |
| 2026-03-12 | JUVENAL, TOBIN W | Chief Commercial Officer | Sale | 20,863 | $25.24 | $526582.12 |
| 2026-03-11 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 6,226 | — | — |
| 2026-03-11 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 17,310 | $26.11 | $451946.79 |
| 2026-03-11 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Buy | 6,226 | $2.39 | $14880.14 |
| 2026-03-11 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,357 | $26.11 | $35429.91 |
| 2026-03-11 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 1,160 | $26.11 | $30286.44 |
| 2026-03-11 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 282 | $26.11 | $7362.74 |
| 2026-03-11 | MAETZOLD, DEREK J | Director, Pres. & Chief Exec. Officer | Sale | 279 | $26.11 | $7284.41 |
Frequently asked questions
Are CSTL insiders buying or selling?
Over the transactions on record, CSTL insiders have been net sellers, with about $4.37M in stock sold across 78 sales, against 7 open-market purchases.
Does insider selling at CSTL mean the stock will fall?
Not by itself. Most executive selling is pre-scheduled through 10b5-1 plans filed months in advance, and insiders sell for diversification, taxes, and liquidity far more often than out of any view on the price. Insider buying is the stronger signal, especially when several insiders buy around the same time, because there is usually only one reason to put personal cash into the stock.
Which CSTL insiders are selling the most?
Recent selling is concentrated in a few names. MAETZOLD, DEREK J accounts for the largest share on record, with about $3.46M sold. Selling by one or two individuals matters less than broad selling across the whole leadership team, which is the pattern worth watching.