MAETZOLD DEREK J 4

What Happened
Derek J. Maetzold, President, CEO and Director of Castle Biosciences (CSTL), sold a total of 4,017 shares in open-market transactions on February 3–4, 2026, generating about $158,757. The filings report three disposals: 3,200 shares at a weighted-average $39.91 ($127,722), 646 shares at $37.82 ($24,433), and 171 shares at $38.61 (~$6,602). These were sales (S), not purchases.

Key Details

• Transaction dates: Feb 3, 2026 (3,200 shares) and Feb 4, 2026 (646 shares and 171 shares).
• Reported prices and ranges:
  • 3,200 shares — weighted avg $39.91; executed in multiple trades at $39.590–$40.360 (footnote F2).
  • 646 shares — weighted avg $37.82; executed in multiple trades at $37.490–$38.080 (footnote F3).
  • 171 shares — weighted avg $38.61; executed in multiple trades at $38.520–$38.885 (footnote F4).
• Total proceeds: ~$158,757.
• Plan/authorization: Transactions were made pursuant to a Rule 10b5-1 plan adopted May 8, 2025 (footnote F1).
• Holdings: The filing references multiple trust holdings associated with Maetzold (footnotes F5–F13). The filing excerpt does not state the total shares owned after these transactions.
• Timeliness: Form 4 was filed Feb 5, 2026; the filing appears timely (no late-filing flag).

Context
Sales under a Rule 10b5-1 plan are prearranged and often scheduled in advance, which can indicate routine disposition rather than a real-time view on the company. For retail investors, purchases tend to carry more direct informational weight; these scheduled sales are a common way for insiders to diversify or meet liquidity needs.