Form 4 for CSTL CASTLE BIOSCIENCES INC
Accepted 2026-03-05 00:00:00 ET · period of report 2026-03-03 · accession 0001628280-26-015352 · SEC index · Original document
Summary rows
Aggregated the way they appear in lists: one row per insider, transaction code and security table.
| X | Filed | Traded | Ticker | Insider | Title | Type | Price | Qty | Owned | ΔOwn | Value |
|---|---|---|---|---|---|---|---|---|---|---|---|
| DM | 2026-03-05 | 2026-03-03+ | CSTL | Oelschlager Kristen M | COO | F - Tax | $28.01 | -9,219 | 39.0K | -19% | -$258.2K |
| D | 2026-03-05 | 2026-03-04 | CSTL | Oelschlager Kristen M | COO | M - OptEx | — | +25.8K | 45.8K | +128% | — |
| DM | 2026-03-05 | 2026-03-04 | CSTL | Oelschlager Kristen M | COO | M - OptEx | $0.00 | -25.8K | 35.9K | -42% | $0 |
| D | 2026-03-05 | 2026-03-03 | CSTL | Oelschlager Kristen M | COO | A - Grant | $0.00 | +48.4K | 48.4K | New | $0 |
Purchase Sale Sale after option exercise All abbreviations
Every reported transaction
| # | Table | Security | Date | Code | A/D | Shares | Price | Owned after | Own | Exercise / expiry | Underlying | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Common | Common Stock | 2026-03-03 | F | D | 2,427 | $27.57 | 20,068 | D | — | — | (F1) Reflects the withholding of shares of the Issuer's common stock to satisfy tax withholding obligations in connection with the delivery of vested performance stock units reported on January 12, 2026. (F2) Includes 965 shares acquired on February 27, 2026, under the Issuer's employee stock purchase plan. |
| 2 | Common | Common Stock | 2026-03-04 | F | D | 6,792 | $28.17 | 39,047 | D | — | — | |
| 3 | Common | Common Stock | 2026-03-04 | M | A | 25,771 | — | 45,839 | D | — | — | (F3) Each Restricted Stock Unit ("RSU") represents the right to receive one share of the Issuer's Common Stock. |
| 4 | Derivative | Restricted Stock Units | 2026-03-04 | M | D | 13,811 | $0.00 | 27,621 | D | — · — to — | 13,811 Common Stock | (F3) Each Restricted Stock Unit ("RSU") represents the right to receive one share of the Issuer's Common Stock. (F6) On March 4, 2024, the Reporting Person was granted 55,243 RSUs which vest in four equal installments beginning on March 4, 2025. |
| 5 | Derivative | Restricted Stock Units | 2026-03-04 | M | D | 11,960 | $0.00 | 35,878 | D | — · — to — | 11,960 Common Stock | (F3) Each Restricted Stock Unit ("RSU") represents the right to receive one share of the Issuer's Common Stock. (F7) On March 4, 2025, the Reporting Person was granted 47,838 RSUs which vest in four equal installments beginning on March 4, 2026. |
| 6 | Derivative | Restricted Stock Units | 2026-03-03 | A | A | 48,367 | $0.00 | 48,367 | D | — · — to — | 48,367 Common Stock | (F3) Each Restricted Stock Unit ("RSU") represents the right to receive one share of the Issuer's Common Stock. (F5) The RSU's vest in four equal annual installments beginning on March 03, 2027. |