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.
Castle Biosciences Inc. insider activity: President, Chief Executive Officer and director Derek J. Maetzold reported open-market sales of common stock under a Rule 10b5-1 trading plan adopted on May 8, 2025. He sold 2,678 shares on January 5, 2026 at a weighted-average price of $38.09 per share and 1,339 shares on January 6, 2026 at a weighted-average price of $40.096 per share, for a total of 4,017 shares sold.
After these transactions, Maetzold directly held 29,513 shares of common stock. He also reported indirect beneficial ownership through multiple trusts, including 52,923 shares held by The Maetzold Descendants 2020 Trust, 44,986 shares held by the Derek Maetzold 2020 Irrevocable Trust, several 2018 remainder trusts each holding 3,615 or 3,618 shares, and 85,959, 18,718 and 44,323 shares held by DJM Grantor Retained Annuity Trusts Nos. 5, 6 and 7, respectively.
Castle Biosciences Inc. reported insider stock sales by its president, chief executive officer and director. On 12/15/2025, the reporting person sold 18,513 shares of common stock at a weighted-average price of $38.747 and 1,012 shares at $39.304. On 12/16/2025, they sold an additional 12,821 shares at a weighted-average price of $38.554. These trades were made under a Rule 10b5-1 trading plan adopted on May 8, 2025. After the reported sales, the reporting person directly owns 34,869 shares of common stock and also has indirect beneficial ownership of multiple blocks of shares through several family and grantor retained annuity trusts.
Castle Biosciences’ chief commercial officer reported selling 13,200 shares of the company’s common stock on 12/11/2025 at a weighted-average price of $37.48 per share. The transaction is disclosed as a sale of non-derivative securities on a Form 4 filing.
Following this sale, the officer directly beneficially owns 86,825 shares of Castle Biosciences common stock. The filing notes that the transaction was executed in multiple trades at prices ranging from $37.31 to $37.72 per share, with the reported price reflecting the weighted-average sale price.
Castle Biosciences' chief financial officer reported an insider stock sale. On 12/11/2025, the officer sold 4,496 shares of common stock at $37.45 per share, leaving 50,326 shares owned directly after the transaction.
Castle Biosciences’ president, chief executive officer and director reported multiple stock transactions tied to restricted stock unit (RSU) vesting. On December 9, 2025, RSUs converted into 33,495 shares of common stock, followed by the disposition of 13,181 shares at $38.25 per share to cover tax obligations. On December 10, 2025, additional RSUs converted into 15,424 shares, with 6,070 shares disposed of at $38.02 per share for taxes, leaving 67,215 shares of common stock held directly.
The reporting person also lists indirect beneficial ownership in Castle Biosciences common stock through several family and grantor retained annuity trusts, each holding separate blocks of shares for the benefit of the reporting person, spouse and children.
Castle Biosciences' Chief Commercial Officer reported equity transactions involving restricted stock units and common stock. On December 9, 2025 and December 10, 2025, the reporting person acquired 15,961 and 6,170 shares of common stock coded "M" in connection with restricted stock units, and disposed of 6,441 and 2,490 shares coded "F" at prices of $38.25 and $38.02 per share.
After these transactions, the officer beneficially owned 100,025 shares of Castle Biosciences common stock directly. The filing also shows 15,961 restricted stock units outstanding from a grant made on December 9, 2022 that vests in four equal installments beginning on December 9, 2023, and notes that 24,679 restricted stock units granted on December 10, 2021 vest in four equal installments beginning on December 10, 2022. The ownership total includes 2,230 shares that were previously held by a family revocable trust and were distributed to the reporting person on February 5, 2025.
Castle Biosciences Inc. reported an insider stock sale by a director who also serves as president and chief executive officer. On December 4, 2025, the insider sold 1,339 shares of common stock at a weighted-average price of $40.03 per share in a transaction made under a contract, instruction or written plan intended to satisfy Rule 10b5-1(c), which was adopted on May 8, 2025.
After this sale, the insider directly owned 37,547 shares of Castle Biosciences common stock and reported additional indirect holdings through several family trusts, including 52,923 shares held by The Maetzold Descendants 2020 Trust and 44,986 shares held by the Derek Maetzold 2020 Irrevocable Trust.
Castle Biosciences, Inc. reported an insider stock sale by a senior executive. The company’s president and chief executive officer, who is also a director, filed a Form 4 showing the sale of 5,115 shares of common stock on 11/25/2025 at a weighted-average price of $40.049 per share.
The filing states that this transaction was made under a pre-arranged Rule 10b5-1 trading plan adopted on May 8, 2025. Following the sale, the executive directly owns 45,822 shares of Castle Biosciences common stock. In addition, the executive reports indirect ownership through several family and grantor retained annuity trusts, including 52,923 shares held by The Maetzold Descendants 2020 Trust and 85,959 shares held by DJM Grantor Retained Annuity Trust No. 5, among other trust holdings.
Castle Biosciences (CSTL) reported insider activity by its Chief Commercial Officer. On 11/20/2025, the officer exercised a stock option to buy 4,693 shares of common stock at $3.38 per share and on the same day sold 4,693 shares in open-market transactions at a weighted-average price of $35.58, with individual trades ranging from $35.40 to $35.85. These trades were carried out under a Rule 10b5-1 trading plan adopted on September 11, 2024.
After the transactions and a 68-share reconciliation adjustment, the officer beneficially owns 84,595 shares directly and 2,230 shares indirectly through a family revocable trust. The officer also holds 11,210 fully vested stock options with a $3.38 exercise price expiring on March 12, 2029.
Castle Biosciences Inc. insider trading report: A reporting person who serves as a director and as President & Chief Executive Officer of Castle Biosciences (CSTL) sold 2,678 shares of common stock on 11/18/2025 at a weighted-average price of $34.02 per share. The sale was made pursuant to a pre-arranged Rule 10b5-1 trading plan adopted on May 8, 2025. After this transaction, the insider directly holds 50,937 shares of common stock and also reports indirect ownership through multiple family and grantor retained annuity trusts, including 52,923 shares held by The Maetzold Descendants 2020 Trust and 44,986 shares held by the Derek Maetzold 2020 Irrevocable Trust.