Castle Biosciences, Inc. (CSTL)

Castle Biosciences' stock has experienced significant volatility, with a 52-week range between $14.59 and $44.28. In Q1 2026, the company reported strong results with revenue of $83.7 million, exceeding forecasts, and increased its full-year revenue guidance, but reported a net loss of $14.5 million. New data presented at the 2026 American Academy of Dermatology Annual Meeting demonstrated that DecisionDx-Melanoma refines mortality risk, and data from Mayo Clinic showed that TissueCypher improves risk stratification for Barrett's esophagus. The company held its Q4 2025 earnings call and released preliminary results, influencing stock performance. A Novitas Local Coverage Determination (LCD) that included DecisionDx-SCC as noncovered impacted test report volume for the nine months ended September 30, 2025.

Castle Biosciences has observed demand seasonality for its products and services, with the first quarter of the year historically experiencing fewer gastrointestinal (GI) procedures compared to other quarters. However, March 2026 was a record month for TissueCypher test reports, and this trend continued into April.

Castle Biosciences, Inc. is a molecular diagnostics company focused on improving health through innovative tests that guide patient care, primarily in dermatologic and gastroenterological diseases. The company develops and commercializes proprietary molecular tests designed to provide personalized, clinically actionable solutions for disease management and improved patient outcomes. Their major products include DecisionDx-Melanoma, a gene expression profile test for invasive cutaneous melanoma; TissueCypher Barrett's Esophagus, a spatialomics test designed to predict the future development of high-grade dysplasia and/or esophageal cancer in patients with Barrett's esophagus; AdvanceAD-Tx, a non-invasive GEP test to guide systemic treatment selection for patients with moderate-to-severe atopic dermatitis; DecisionDx-SCC, a GEP test for cutaneous squamous cell carcinoma; MyPath Melanoma, a diagnostic GEP test used for patients with difficult-to-diagnose melanocytic lesions; and DecisionDx-UM, a GEP test that predicts the risk of metastasis for patients with uveal melanoma. The company generates revenue through the delivery of test reports for its molecular diagnostic tests.

Castle Biosciences' corporate headquarters is located in Friendswood, Texas. The company also operates laboratory facilities in Phoenix, Arizona, and Pittsburgh, Pennsylvania.

Castle Biosciences has cultivated a positive brand reputation, emphasizing its commitment to improving health through innovative tests and a strong workforce culture. In September 2025, Castle Biosciences was included in Newsweek's inaugural "America's Greatest Companies 2025" list and has been recognized as a "Top Workplace" in Houston and Pittsburgh. The company consistently highlights its mission to empower patients and healthcare providers by combining innovation, advanced technologies, and relevant real-world evidence.

The ownership structure of Castle Biosciences is a mix of institutional, retail, and insider holdings. Institutional investors hold a significant majority of the company's stock. Major institutional shareholders include BlackRock, Inc., Vanguard Group Inc., RTW Investments, LP, and others. Insiders, including CEO Derek J. Maetzold, hold a notable percentage of the shares. Retail investors also hold a substantial portion of the stock.