Castle Biosciences COO Kristen Oelschlager Exercises Options, Sells Shares

What Happened
Kristen M. Oelschlager, Chief Operating Officer of Castle Biosciences (CSTL), exercised 4,152 option shares on September 1, 2026 at an exercise price of $3.38 (cost ~$14,034) and sold those 4,152 shares in open-market transactions the same day for total proceeds of about $138,643 (weighted-average sale price ≈ $33.36). The sale was executed in multiple trades; prices reported range from $33.015 to $33.900. Overall, this looks like an option exercise followed by an immediate sale of the exercised shares (a cashless-style transaction).

Key Details

• Transaction date: September 1, 2026.
• Exercise: 4,152 shares @ $3.38 = $14,034 (acquired).
• Sales: 3,952 shares @ $33.36 = $131,839; 200 shares @ $34.02 = $6,804; total ≈ $138,643 (disposed). Weighted-average sale price reflects multiple trade prices ($33.015–$33.900).
• The filing shows a corresponding derivative disposition entry for 4,152 shares at $0.00 (this records the conversion/exercise).
• Shares owned after the transaction are not explicitly stated in the filing; the sold shares equal the shares acquired by this exercise, so she appears to have sold all shares produced by this exercise.
• Footnotes: trades were executed under a Rule 10b5-1 trading plan adopted March 17, 2026 (F1); the filing references 68 shares from an ESPP acquired Aug 31, 2026 (F2); option shares were fully vested (F5); some shares are held in a family trust (F4).
• Filing appears timely (filed Sept 3 for Sept 1 transactions).

Context
When an insider exercises options and then sells the resulting shares the same day, it’s commonly a cashless exercise to realize gains or cover tax/option costs rather than a directional vote on the stock. The presence of a 10b5-1 plan means the sales were pre-planned and intended to comply with insider-trading rules. This is routine insider liquidity rather than a clear buy signal.