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.
Derek Maetzold reported proposed sales of Common shares of CSTL under Rule 144, listing multiple transactions dated between 01/05/2026 and 03/18/2026.
The filing lists numerous individual dispositions by Mr. Maetzold and related trusts, with transaction entries showing share counts and dollar values for each trade, including a 23,179-share entry on 03/12/2026. The filing is a disclosure of proposed/resale transactions under Rule 144.
Castle Biosciences Inc ownership update: The Vanguard Group filed an amendment reporting it beneficially owns 0 shares (0%) of Castle Biosciences common stock as disclosed in this Schedule 13G/A.
The filing explains an internal realignment of Vanguard subsidiaries that resulted in disaggregated reporting under SEC Release No. 34-39538. The filing is signed by Ashley Grim, Head of Global Fund Administration.
Castle Biosciences CEO Derek J. Maetzold reported open-market sales of 19,300 shares of Common Stock of CASTLE BIOSCIENCES INC. He sold 18,650 shares at a weighted-average price of $25.93 on March 17, 2026 and 650 shares at $25.39 on March 18, 2026, leaving 21,479 shares held directly.
The filing notes these transactions were executed under a pre-arranged Rule 10b5-1 trading plan adopted on December 3, 2025. Maetzold also reports indirect ownership of additional Common Stock through multiple family and grantor retained annuity trusts, including 51,566 shares held by The Maetzold Descendants 2020 Trust and other trusts where he serves as trustee or beneficiary.
Castle Biosciences Inc. President and CEO Derek J. Maetzold reported open-market sales of a total of 30,779 shares of common stock on March 13 and 16, 2026, at weighted-average prices of $25.447, $25.964 and $26.680 per share. These transactions were made under a pre-arranged Rule 10b5-1 trading plan adopted on December 3, 2025. Following the sales, he holds 40,779 shares directly and also has indirect holdings through several family and grantor retained annuity trusts.
CASTLE BIOSCIENCES INC Chief Commercial Officer Juvenal Tobin reported an open-market sale of 20,863 shares of common stock. The shares were sold at a weighted-average price of $25.24 per share, with individual trade prices ranging from $24.90 to $25.70. After this transaction, Tobin directly holds 86,825 shares. The sale was made under a pre-arranged Rule 10b5-1 trading plan adopted on December 10, 2025, indicating the timing was set in advance rather than decided opportunistically.
Castle Biosciences President and CEO Derek J. Maetzold reported a pre-planned combination of option exercise and share sales. On March 11, 2026, he exercised a fully vested stock option for 6,226 shares of common stock at $2.39 per share and received the underlying shares.
That same day, Maetzold and several family-related trusts sold multiple blocks of common stock in open-market transactions at a weighted-average price of about $26.11. On March 12, 2026, he sold an additional 23,179 shares at an average price of $25.279 per share. All sales were made pursuant to a Rule 10b5-1 trading plan adopted on December 3, 2025. After these trades, he holds 71,558 shares directly, plus additional indirect holdings through various trusts.
CSTL filed a Form 144 reporting proposed sales of Common Stock. The notice lists 20,863 shares with an aggregate market value of $528,251.16 and records a prior sale of 13,200 shares on 12/11/2025 by Tobin Juvenal. The filing identifies recent grants of restricted and performance stock units dated 03/03/2026 and 03/04/2026.
CSTL filing: Notice of proposed sales of Common Stock by reporting person Derek Maetzold
The filing lists multiple dispositions of Common stock by Derek Maetzold under a Form 144 notice, describing sales executed on various dates and securities acquired by gift and compensation (RSUs, PSUs, options). Several transactions in late 2025 and early 2026 are itemized with share counts and proceeds.
Castle Biosciences Chief Financial Officer Frank Stokes sold 6,001 shares of common stock on March 5, 2026 in an open-market transaction at a weighted-average price of $27.98 per share. The sale was made under a prearranged Rule 10b5-1 trading plan adopted on November 13, 2025.
The transaction was executed in multiple trades at prices ranging from $27.51 to $28.41 per share, with the reported price reflecting the weighted average. After this planned sale, Stokes continues to directly own 60,085 shares of Castle Biosciences common stock.
Castle Biosciences director Cole G Bradley reported option exercises and stock sales. On March 5, 2026, Bradley exercised stock options for 4,748 shares and received an equal number of common shares. He then sold a total of 7,403 common shares in open-market transactions and held 19,309 shares directly afterward.