Castle Biosciences (CSTL) CEO Derek Maetzold Sells Shares

What Happened
Derek J. Maetzold, President & CEO and a director of Castle Biosciences (CSTL), exercised options and sold company stock on August 14, 2026. He exercised a total of 2,200 option-derived shares (two entries of 1,100 shares each); 1,100 shares were acquired at $2.39 per share (cost ~$2,629) and 1,100 shares were reported as disposed at $0.00 (surrender/withheld). Separately, he sold 7,232 shares in open-market trades at a weighted-average price of $30.02 for total proceeds of about $217,106. These sales were made pursuant to a pre-established Rule 10b5‑1 trading plan.

Key Details

• Transaction date: August 14, 2026; Form filed Aug 18, 2026 (timely filing).
• Sales: 7,232 shares sold; weighted-average sale price $30.02; reported proceeds ≈ $217,106. Reported execution prices ranged $29.73–$30.55 (multiple trades).
• Option activity: Two derivative (M) entries of 1,100 shares each — one acquired at $2.39 (paid ~$2,629), one disposed at $0.00 (surrender/withheld). Footnote F13 notes the options were fully vested.
• Plan/notes: Sales executed under a Rule 10b5‑1 plan adopted Dec 3, 2025 (F1). Several holdings are held in family trusts (F3–F12) as disclosed in the filing.
• Shares owned after the transaction: not specified in the provided excerpt.

Context

• This was an exercise of options followed by open‑market sales; the reported pattern (acquire/surrender and immediate market sales) is consistent with a net/partial cashless exercise and preplanned dispositions rather than a single open‑market purchase.
• The Rule 10b5‑1 plan means the sales were made under a pre-established trading program, which is commonly used to avoid timing concerns; it does not by itself indicate the insider’s view of the company.