Form 4 Filing for Derek J. Maetzold

Derek J. Maetzold, President & CEO of CASTLE BIOSCIENCES INC (CSTL), reported several transactions on September 21, 2026. Maetzold acquired 8,580 shares of Common Stock at $2.39 per share. He also disposed of 8,580 shares at a weighted-average price of $35.334, executed through multiple trades. Additionally, he disposed of 3,198 shares held indirectly through The Maetzold Descendants 2020 Trust and 2,718 shares held indirectly through the Derek Maetzold 2020 Irrevocable Trust, both at a weighted-average price of $35.334. These transactions were made pursuant to a Rule 10b5-1 plan. Maetzold also exercised a stock option for 8,580 shares of Common Stock.