Form 4: Castle Biosciences CEO Sells Shares Under 10b5-1 Plan

Castle Biosciences' President and CEO, Derek J. Maetzold, sold 4,258 shares of common stock for approximately $40.09 per share under a pre-arranged 10b5-1 trading plan.

Summary

• Derek J. Maetzold, President & CEO and Director of Castle Biosciences Inc. (CSTL), sold 4,258 shares of common stock.
• The transaction occurred on November 26, 2025, at a weighted-average price of $40.09 per share, with trades ranging from $40.00 to $40.42.
• This sale was executed pursuant to a Rule 10b5-1 trading plan adopted by Mr. Maetzold on May 8, 2025.
• Following the transaction, Mr. Maetzold directly beneficially owns 41,564 shares and indirectly owns 261,372 shares through various trusts.

Sentiment

Score: 5

Explanation: The sale is a routine insider transaction under a pre-arranged 10b5-1 plan, which typically has a neutral to slightly negative sentiment as it's not a strong signal of future performance but does reduce insider ownership.

Positives

• The sale was conducted under a pre-arranged Rule 10b5-1 plan, indicating it was not based on new, non-public information.

Negatives

• An insider sale, even if planned, reduces the direct ownership stake of a key executive.

Related Party Transactions

• Shares are indirectly held by various trusts, including The Maetzold Descendants 2020 Trust, Derek Maetzold 2020 Irrevocable Trust, Maetzold 2018 Remainder Trusts FBO children, and DJM Grantor Retained Annuity Trusts, where Mr. Maetzold or his spouse are trustees or beneficiaries.

Stakeholder Impact

• Minimal direct impact on shareholders as this is a routine, pre-planned insider sale of a relatively small portion of the executive's total beneficial ownership.

Key Dates

Recommendation

This Form 4 reports a pre-scheduled sale by the CEO under a 10b5-1 plan. Such transactions are generally not indicative of a change in the company's fundamental outlook or a strong signal for future stock performance. Therefore, it does not warrant a change in investment recommendation based solely on this filing.

Keywords

Castle Biosciences, CSTL, Derek Maetzold, Insider Sale, Form 4, 10b5-1 Plan, Common Stock, Executive Transaction