Castle Biosciences CEO trades 4,172 shares
Sentiment and the balance of points
Rhea-AI Sentiment reads the wording of the document, how positive or negative its language is on a 1 to 5 scale. The balance of points shown with the takes weighs what the document actually discloses, so the two can disagree, for example when a trial that missed its main goal is described in upbeat language.
Form Type
4
Rhea-AI Filing Summary
Castle Biosciences Inc. President and Chief Executive Officer Derek J. Maetzold reported open-market sales of 4,172 shares of common stock on July 14, 2026 at a weighted-average price of about $22.92 per share, executed largely through family trusts and related entities.
He also exercised stock options for 550 shares at an exercise price of $2.39 per share. The sales were carried out under a Rule 10b5-1 trading plan adopted on December 3, 2025, and many positions are reported as indirect holdings through various Maetzold family trusts and grantor retained annuity trusts.
Insider Trade Summary 10b5-1
Exercise and sale activity reported; no spread calculated
Exercise and Sale
12 txns
Insider
MAETZOLD DEREK J
Role
Pres. & Chief Exec. Officer
Sold
4,172 shs ($96K)
Approx. gross sale proceeds
$96K
Approx. exercise cost
$1K
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Exercise | Stock option (right to buy) F1, F12 | 550 | $0.00 | $0.00 |
| Exercise | Common Stock F1 | 550 | $2.39 | $1K |
| Sale | Common Stock F1, F2 | 550 | $22.92 | $13K |
| Sale | Common Stock F1, F2, F3 | 1,357 | $22.92 | $31K |
| Sale | Common Stock F1, F2, F4 | 1,153 | $22.92 | $26K |
| Sale | Common Stock F1, F2, F5 | 278 | $22.92 | $6K |
| Sale | Common Stock F1, F2, F6 | 278 | $22.92 | $6K |
| Sale | Common Stock F1, F2, F7 | 278 | $22.92 | $6K |
| Sale | Common Stock F1, F2, F8 | 278 | $22.92 | $6K |
| holding | Common Stock F9 | -- | -- | -- |
| holding | Common Stock F10 | -- | -- | -- |
| holding | Common Stock F11 | -- | -- | -- |
Holdings After Transaction:
Stock option (right to buy) — 85,117 contracts (Direct);
Common Stock — 21,479 shares (Direct);
Common Stock — 39,353 shares (Indirect, By The Maetzold Descendants 2020 Trust);
Common Stock — 33,449 shares (Indirect, By Derek Maetzold 2020 Irrevocable Trust);
Common Stock — 12,090 shares (Indirect, By The Maetzold 2018 Remainder Trust FBO Emily Carol Kirk);
Common Stock — 12,090 shares (Indirect, By The Maetzold 2018 Remainder Trust FBO Hannah Elizabeth Maetzold);
Common Stock — 12,090 shares (Indirect, By The Maetzold 2018 Remainder Trust FBO John Derek Maetzold);
Common Stock — 12,090 shares (Indirect, By The Maetzold 2018 Remainder Trust FBO Peter Douglas Maetzold);
Common Stock — 18,718 shares (Indirect, By DJM Grantor Retained Annuity Trust No. 6);
Common Stock — 44,323 shares (Indirect, By DJM Grantor Retained Annuity Trust No. 7);
Common Stock — 40,935 shares (Indirect, By DJM Grantor Retained Annuity Trust No. 8)
Footnotes (12)
- F1. These transactions were made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on December 3, 2025.
- F2. This transaction was executed in multiple trades at prices ranging from $22.62 to $23.15, inclusive. The price reported above reflects the weighted-average sale price. The Reporting Person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.
- F3. Held by The Maetzold Descendants 2020 Trust of which the Reporting Person's spouse is the trustee and the Reporting Person's spouse and their children are beneficiaries.
- F4. Held by Derek Maetzold 2020 Irrevocable Trust of which the Reporting Person is the trustee and his children are beneficiaries.
- F5. Held by The Maetzold 2018 Remainder Trust FBO Emily Carol Kirk of which the Reporting Person is the trustee and his child is the beneficiary.
- F6. Held by The Maetzold 2018 Remainder Trust FBO Hannah Elizabeth Maetzold of which the Reporting Person is the trustee and his child is the beneficiary.
- F7. Held by The Maetzold 2018 Remainder Trust FBO John Derek Maetzold of which the Reporting Person is the trustee and his child is the beneficiary.
- F8. Held by The Maetzold 2018 Remainder Trust FBO Peter Douglas Maetzold of which the Reporting Person is the trustee and his child is the beneficiary.
- F9. Held by DJM Grantor Retained Annuity Trust No. 6 of which the Reporting Person is the trustee and the beneficiaries are The Maetzold 2018 Remainder Trust FBO John Derek Maetzold, The Maetzold 2018 Remainder Trust FBO Emily Carol Kirk, The Maetzold 2018 Remainder Trust FBO Peter Douglas Maetzold and The Maetzold 2018 Remainder Trust FBO Hannah Elizabeth Maetzold.
- F10. Held by DJM Grantor Retained Annuity Trust No. 7 of which the Reporting Person is the trustee and beneficiary.
- F11. Held by DJM Grantor Retained Annuity Trust No. 8 of which the Reporting Person is the trustee and beneficiary.
- F12. The shares subject to the option are fully vested.
Key Figures
Common shares sold: 4,172 shares
Weighted-average sale price: $22.9200 per share
Sale price range: $22.62 to $23.15 per share
+4 more
7 metrics
Common shares sold
4,172 shares
Total non-derivative common shares sold on July 14, 2026
Weighted-average sale price
$22.9200 per share
Price reported for open-market sales of CSTL common stock
Sale price range
$22.62 to $23.15 per share
Range of execution prices for the reported common stock sales
Options exercised into common stock
550 shares
Common shares acquired through stock option exercise on July 14, 2026
Option exercise price
$2.3900 per share
Exercise price of the stock option converted into common shares
Maetzold Descendants 2020 Trust holding
39,353 shares
Common shares shown following the reported sale for that trust
Derek Maetzold 2020 Irrevocable Trust holding
33,449 shares
Common shares shown following the reported sale for that trust
Key Terms
Rule 10b5-1 plan, Grantor Retained Annuity Trust, Stock option (right to buy), weighted-average sale price
4 terms
Rule 10b5-1 plan regulatory
"These transactions were made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person."
A Rule 10b5-1 plan is a prearranged, written schedule that lets corporate insiders buy or sell company stock at set times or amounts, even if they later learn material nonpublic information. Think of it like setting an automatic thermostat for trades: it creates a clear record that trades were planned in advance, reducing the risk of insider-trading accusations and helping investors trust that insider transactions are routine rather than based on secret information.
Grantor Retained Annuity Trust financial
"Held by DJM Grantor Retained Annuity Trust No. 7 of which the Reporting Person is the trustee."
A grantor retained annuity trust (GRAT) is an estate-planning tool where the person who creates the trust transfers assets into it but receives fixed cash payments (an annuity) from the trust for a set number of years; whatever remains after that term passes to designated beneficiaries. It matters to investors because it can shift future appreciation of assets out of the creator’s taxable estate—like putting an asset into a timed vending machine that pays you fixed amounts while any extra value that grows inside the machine goes to heirs with reduced gift or estate tax consequences.
Stock option (right to buy) financial
"Security title is Stock option (right to buy) with an expiration date in 2028."
weighted-average sale price financial
"The price reported above reflects the weighted-average sale price for the trades."
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
What insider transactions did Castle Biosciences (CSTL) CEO Derek Maetzold report?
Derek Maetzold reported open-market sales of 4,172 Castle Biosciences shares on July 14, 2026 at a weighted-average price of $22.92 per share, and separately exercised stock options for 550 shares at an exercise price of $2.39 per share.
Were Derek Maetzold’s Castle Biosciences (CSTL) trades under a Rule 10b5-1 plan?
Yes. A footnote states these transactions were made pursuant to a Rule 10b5-1 plan adopted by Derek Maetzold on December 3, 2025, indicating the trades were pre-arranged rather than discretionary in timing, which affects how investors may interpret their significance.
Did Derek Maetzold exercise Castle Biosciences (CSTL) stock options in this filing?
Yes. He exercised stock options for 550 shares of Castle Biosciences common stock at an exercise price of $2.39 per share. A footnote explains that the shares subject to the option are fully vested, and the option is described as a stock option right to buy common stock.
AI-generated analysis. How Rhea-AI works. Not financial advice.
Accepted by SEC EDGAR
Learn about SEC filing dates