CASTLE BIOSCIENCES INC
Castle Biosciences, Inc. (NASDAQ: CSTL) is a molecular diagnostics company that develops and commercializes proprietary gene expression profile and spatialomics tests to aid clinicians in the diagnosis and treatment of dermatologic cancers, Barrett's esophagus, atopic dermatitis, and uveal melanoma. Founded in 2008,… From the company’s description.
Margins and return on equity change in ; everything else in percent. Fewer shares and less debt are shown plainly, not as bad news — it depends what you make of buybacks. Dotted labels explain each measure. is shown separately from the annual figures.
What CASTLE BIOSCIENCES INC does
In the company’s own words
Castle Biosciences, Inc. (NASDAQ: CSTL) is a molecular diagnostics company that develops and commercializes proprietary gene expression profile and spatialomics tests to aid clinicians in the diagnosis and treatment of dermatologic cancers, Barrett's esophagus, atopic dermatitis, and uveal melanoma. Founded in 2008, the company operates clinical laboratory facilities in Phoenix, Arizona and Pittsburgh, Pennsylvania, both of which are CLIA-certified and CAP-accredited.
The company's core test portfolio includes DecisionDx-Melanoma, designed to predict metastasis risk in cutaneous melanoma patients; TissueCypher, a spatialomics test for Barrett's esophagus risk stratification; DecisionDx-SCC, which predicts treatment responsiveness in squamous cell carcinoma; MyPath Melanoma, a diagnostic test for difficult-to-diagnose melanocytic lesions; DecisionDx-UM, a risk stratification test for uveal melanoma; and AdvanceAD-Tx, a recently launched test to guide systemic treatment selection for moderate-to-severe atopic dermatitis. The company delivered approximately 105,000 test reports across its portfolio during 2025, generating net revenues of approximately $344 million.
Castle Biosciences employs a direct sales and marketing strategy focused on educating clinicians and key opinion leaders on the clinical and economic benefits of its products. The company's revenue is primarily derived from third-party payor reimbursement, including Medicare and commercial insurance providers. Medicare accounted for approximately 44 percent of patient-derived revenue in 2025, with a single commercial payor representing 16 percent of revenue.
The company has secured intellectual property protection through a global patent portfolio comprising 156 patent families as of December 31, 2025, with filing dates ranging from 2007 to 2045. Castle Biosciences maintains 24 trademark registrations and relies on trade secrets and continuing technological innovation to maintain competitive positioning. The company has expanded its capabilities through strategic acquisitions, including Cernostics in 2021, AltheaDx in 2022, and Previse in 2025, which enhanced its gastrointestinal testing portfolio. The company's website is www.castlebiosciences.com.
Company details
- Sector
- Healthcare
- Industry
- Health Services
- Headquarters
- FRIENDSWOOD, TX
- Fiscal year end
- December
- CIK
- 1447362
- SIC
- 8071
Financial performance, year by year
Fiscal 2019–2025 · USDThe full income statement, balance sheet and cash flow for each of these years — every figure traceable to its filing — is on the Financials tab with a free account.
Who owns CASTLE BIOSCIENCES INC — and what changed
Funds as of 2026Q2 · superinvestors as of 2026-06-30
Largest fund holders · CASTLE BIOSCIENCES INC’s weight in each
Fund ownership is a floor, not a census — pensions, insurers and people holding shares directly are not visible here.
Fund ownership counts N-PORT filers only, so it is a floor rather than a census — pensions, insurers and direct holders are not visible here, and the remainder is not “held by individuals”.
Every fund and institutional holder, quarter by quarter, is on the Ownership tab with a free account.
Recent filings
All filings →Each filing opens into its own statements and disclosures here.
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