Welcome to our dedicated page for Castle Biosciences SEC filings (Ticker: CSTL), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
Castle Biosciences, Inc. filings document the regulatory record for a Delaware molecular diagnostics company with common stock listed on the Nasdaq Global Market under CSTL. Recent Form 8-K filings report quarterly and annual operating results, preliminary performance updates, and Regulation FD slide presentations tied to management communications.
The company’s proxy materials cover annual meeting matters, executive compensation, director elections, stockholder voting procedures, and governance disclosures. Other material-event filings document amendments to bylaws, including provisions related to stockholder meetings, director nominations, and board governance, alongside standing disclosures on registered securities and exchange listing status.
Filing type: Rule 144 notice for proposed sale of securities by an affiliate of Castle Biosciences (CSTL).
The filer plans to sell 4,017 shares of common stock through Goldman Sachs & Co. LLC on 08/15/2025, with an aggregate market value of $80,701.53. The company reports 29,008,281 shares outstanding. The shares to be sold were acquired on 08/09/2024 as performance awards and were paid as compensation.
The filing also discloses multiple prior sales by related persons in the past three months, including transactions on 06/27/2025 (several sellers totaling multiple thousands of shares with gross proceeds listed) and a larger sale by Derek Maetzold of 43,019 shares on 08/13/2025 for $836,452.83. The notice includes the filers certification regarding absence of undisclosed material adverse information.
Derek J. Maetzold, President, CEO and Director of Castle Biosciences (CSTL), reported an insider sale under a Rule 10b5-1 plan. On 08/13/2025 he disposed of 43,019 shares of Castle common stock in multiple trades at a weighted-average sale price of $19.504 per share, reducing his direct holdings to 69,683 shares. The filing lists multiple indirect holdings across trusts (largest indirect positions: 85,959; 52,923; 44,986; 44,323; 18,718 shares) that remain held by various family and grantor retained annuity trusts. The 10b5-1 plan was adopted on November 11, 2024. The form is a routine Section 16 disclosure of an executed sale plan.
Castle Biosciences (CSTL) disclosed a proposed sale of 43,019 common shares through Goldman Sachs & Co. LLC with an aggregate market value of $834,998.79. The form lists the approximate date of sale as 08/13/2025 and identifies the securities exchange as NASD. The shares were recorded as acquired on 08/08/2025 from the issuer as performance award compensation, with payment dated 08/08/2025. The filing also reports multiple related-party sales on 06/27/2025 by The Maetzold trusts and Derek Maetzold totaling specific share amounts and gross proceeds. The filer certifies compliance with Rule 144 and affirms no undisclosed material adverse information.
Derek Maetzold, President & CEO and a director of Castle Biosciences (CSTL), reported the conversion of 66,991 performance-based stock units into common shares and a sale of 23,972 shares at $19.36 on 08/08/2025. After the reported sale his direct beneficial ownership is shown as 112,702 shares. The filing documents trust movements on July 11, 2025 (transfers into his direct holdings) and July 14, 2025 (transfer of 44,323 shares from his direct holdings to a grantor retained annuity trust). The PSUs converted represent the remaining 50% of a December 23, 2022 grant that vested in full on the one-year anniversary of August 9, 2024.
Frank Stokes, Chief Financial Officer of Castle Biosciences (CSTL), reported both an issuance and a sale of company stock on 08/08/2025. He received 9,744 shares through the settlement of performance-based stock units (PSUs) at no cash cost; those PSUs are described as the remaining 50% of PSUs granted on December 23, 2022 that vested in full on the one-year anniversary of August 9, 2024. The filing also discloses a sale of 4,356 shares at $19.36 per share.
The filing lists beneficial ownership amounts of 53,072 shares following the acquisition and 48,716 shares following the sale. Based on the reported numbers, Stokes' holdings increased by 5,388 shares net (9,744 acquired minus 4,356 sold). The transactions are reported on a Form 4 filed by the reporting officer.
Kristen M. Oelschlager, Chief Operating Officer and Director of Castle Biosciences, Inc. (CSTL), reported transactions on 08/08/2025 on a Form 4. The filing shows an acquisition of 10,640 shares of common stock at a reported price of $0, and a disposition of 2,804 shares at $19.36 per share. The filing records 171,800 shares beneficially owned following the reported transactions. Table II and the explanation state these 10,640 units relate to Performance-Based Stock Units (PSUs), each representing one share; the PSUs comprised the remaining 50% of a grant made on December 23, 2022, which vested on August 9, 2024.
Castle Biosciences insider activity: The reporting person, Tobin W. Juvenal (Chief Commercial Officer), reported acquisition and disposition of common stock on 08/08/2025. He acquired 10,640 shares through performance-based stock units (PSUs) at $0 and disposed of 4,294 shares at $19.36. The PSUs are described as representing one share each and constitute the remaining 50% of a grant from December 23, 2022, which vested on August 9, 2024.
After the reported transactions the form shows 84,527 shares directly beneficially owned and 2,230 shares held indirectly by the Tobin W. and Susan M. Juvenal Family Revocable Trust. The report was submitted on behalf of the reporting person by an attorney-in-fact.
On August 5, 2025, Castle Biosciences, Inc. adopted amended and restated bylaws effective the same date. The A&R Bylaws revise stockholder nomination and advance-notice procedures by requiring nominees to be stockholders of record at the annual meeting, expanding disclosure and certification obligations for proponents and nominees, limiting the number of stockholder-submitted nominees to the number of directors up for election, and incorporating the Rule 14a-19 universal proxy requirements. The bylaws change meeting mechanics by setting quorum as a majority of voting power, making approval the majority of votes cast (excluding abstentions and broker non-votes), adjusting the annual-meeting alternative window (applies if advanced by more than 30 days or delayed by more than 70 days), and clarifying special meeting procedures. Other amendments update indemnification and expense-advancement provisions, refer to the certificate of incorporation for certain determinations, and require the full A&R Bylaws be filed as Exhibit 3.1.