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. files its annual report describing its 2025 operations, growth, risks and regulatory environment as a molecular diagnostics company focused on dermatology, gastroenterology, ophthalmology and atopic dermatitis.
In 2025, Castle generated $344.2 million in net revenues and delivered 105,053 clinical test reports, up from 96,071 in 2024. Dermatologic tests accounted for 60,665 reports, while TissueCypher Barrett’s esophagus testing rose sharply to 39,014 reports. The company commenced a limited launch of its non-invasive AdvanceAD‑Tx test for moderate‑to‑severe atopic dermatitis.
The report details broad Medicare and commercial coverage for key tests such as DecisionDx‑Melanoma, TissueCypher, MyPath Melanoma, DecisionDx‑UM and (until discontinued) IDgenetix, with specific ADLT-based Medicare rates. It also explains that DecisionDx‑SCC is now non‑covered under finalized Medicare LCDs, which Castle is seeking to reconsider. Extensive risk disclosures emphasize dependence on a small number of third‑party payors, historical losses, evolving FDA and LDT regulation, intellectual property protection, and complex federal and state healthcare and privacy laws.
Castle Biosciences reported modest revenue growth for 2025 but a return to losses as reimbursement and amortization headwinds weighed on results. Full-year revenue was $344.2 million, up 4% from 2024, while total test reports for core dermatologic and GI drivers DecisionDx-Melanoma and TissueCypher grew 37%. TissueCypher volumes nearly doubled, rising to 39,014 tests from 20,956.
Despite strong volume, Medicare coverage changes for DecisionDx-SCC and discontinuation of IDgenetix limited top-line growth. Gross margin was 69% and Adjusted Gross Margin 80%, down from 79% and 82% in 2024, affected by lower DecisionDx-SCC revenue and a one-time $20.1 million amortization acceleration. Full-year net cash from operations was resilient at $64.3 million.
The company swung to a 2025 net loss of $24.2 million, versus net income of $18.2 million in 2024, with net loss per share of $0.83 and Adjusted Net Loss per Share of $0.14. Adjusted EBITDA declined to $44.0 million from $75.0 million. As of December 31, 2025, cash, cash equivalents and marketable securities totaled $299.5 million. Fourth-quarter revenue was $87.0 million, essentially flat year over year, with a quarterly net loss of $2.3 million. For 2026, Castle guides to total revenue of $340–350 million, implying roughly stable sales as it focuses on expanding adoption of its test portfolio, including the new AdvanceAD-Tx atopic dermatitis test.
Castle Biosciences, Inc. has a new large shareholder disclosure. RTW Investments, LP and its managing partner, Roderick Wong, M.D., report beneficial ownership of 2,115,237 shares of Castle Biosciences common stock, representing 7.2% of the company’s outstanding shares based on 29,188,659 shares outstanding as of October 27, 2025.
The shares are held by funds advised by RTW Investments, which have the right to receive dividends and sale proceeds. The filing states the position is held in the ordinary course of business and not for the purpose of changing or influencing control of Castle Biosciences.
Castle Biosciences president and CEO Derek J. Maetzold sold 4,017 shares of common stock in early February 2026 under a pre-arranged Rule 10b5-1 trading plan. Sales included 3,200 shares on February 3 at a weighted-average price of $39.913 and two sales on February 4 totaling 817 shares at weighted-average prices of $37.822 and $38.61. After these transactions, he directly held 83,698 common shares. He also reported indirect beneficial ownership of additional Castle Biosciences shares through multiple family and grantor retained annuity trusts.
Castle Biosciences Inc.’s President and Chief Executive Officer, Derek J. Maetzold, reported a planned sale of common stock under a pre-established Rule 10b5-1 trading plan. On January 20, 2026, he sold 4,017 shares of common stock at a weighted-average price of $40.013 per share in multiple trades within a disclosed price range.
Following this sale, Maetzold directly holds 87,715 shares of Castle Biosciences common stock, and additional shares are held indirectly through various family and grantor retained annuity trusts for which he or his spouse serves as trustee or beneficiary. The filing reflects an orderly, pre-planned diversification step rather than an ad hoc transaction.
Dimensional Fund Advisors LP filed an amended Schedule 13G reporting passive ownership of common stock of Castle Biosciences Inc. Dimensional reports beneficial ownership of 1,143,799 shares, representing 3.9% of Castle Biosciences’ common stock as of the event date. It has sole voting power over 1,117,422 shares and sole dispositive power over 1,143,799 shares.
The filing explains that these shares are owned by various funds and accounts for which Dimensional or its subsidiaries act as investment adviser or manager. Dimensional states that it may be deemed a beneficial owner for Section 13(d) purposes but disclaims beneficial ownership of the securities, which are held by the underlying funds. The filing also certifies that the shares were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of Castle Biosciences.
Castle Biosciences reported that President and CEO Derek J. Maetzold received equity awards tied to performance. On January 12, 2026, 62,219 performance-based stock units (PSUs) granted on March 4, 2024 vested after the board certified that specific performance criteria were met. Each PSU converts into one share of common stock, so Maetzold acquired 62,219 shares of common stock at $0 per share, bringing his directly held common stock to 91,732 shares.
The filing also lists additional common stock held indirectly through various family and grantor retained annuity trusts for estate and family planning purposes. A remaining block of 62,219 PSUs from the 2024 grant is still outstanding and will vest only if stated milestones are achieved.
Castle Biosciences Chief Operating Officer Kristen M. Oelschlager reported equity awards tied to performance. On January 12, 2026, she received 9,207 Performance-Based Stock Units (PSUs), each representing the right to one share of common stock at a price of $0. On the same date, 9,207 shares of common stock were acquired at $0 upon vesting of 50% of PSUs granted on March 4, 2024, after the board certified that performance criteria were met.
Following these transactions, she directly holds 21,530 shares of Castle Biosciences common stock and indirectly holds 97,251 shares through The Fritz Shorter Trust, where she and her spouse are trustees and beneficiaries. The reported PSUs represent the remaining 50% of the 2024 performance-based grant, which will vest only if additional milestones are achieved.
Castle Biosciences reported that Chief Commercial Officer Juvenal Tobin received common stock as performance-based compensation. On January 12, 2026, 9,207 Performance-Based Stock Units (PSUs) from a grant made on March 4, 2024 vested after the board certified that certain performance criteria were met.
Each PSU converts into one share of Castle Biosciences common stock, so 9,207 shares of common stock were acquired at a price of $0 per share. Following this transaction, Tobin beneficially owned 96,032 shares of common stock directly, and 9,207 PSUs remain outstanding, which will vest only if additional milestones are achieved.
Castle Biosciences Chief Financial Officer Frank Stokes reported equity awards tied to performance-based stock units. On 01/12/2026, 8,124 Performance-Based Stock Units (PSUs) granted on March 4, 2024 vested after the board certified that certain performance criteria were met, resulting in the acquisition of 8,124 shares of common stock at a price of $0 per share.
These vested PSUs represent 50% of the 2024 PSU grant. The remaining 50% of the 2024 PSUs, representing an additional 8,124 PSUs, will vest only if specified milestones are achieved. Following the transaction, Stokes beneficially owns 58,450 shares of common stock directly and 8,124 PSUs.