CSTL Stock Forecast & Price Target

Castle Biosciences is supported by strong fundamental momentum, highlighted by Q3’26 revenue of $103M, an 11% beat, and adjusted EBITDA of $13M on a 12% margin, while cash of $278M provides balance-sheet flexibility. Its outlook is further strengthened by durable ASP improvement, rapid TissueCypher growth of 47% year over year, and management’s higher 2026 revenue guide of $385M-$395M, which suggests execution is broadening across the portfolio. The stock also has multiple underappreciated catalysts, including a possible return of SCC Medicare coverage in 2028, early traction in AdvanceAD-Tx with 1,109 tests in Q3’26, and expanding utilization in DecisionDx-Melanoma and TissueCypher.

Castle Biosciences is facing a fundamental revenue setback because meaningful sales from its SCC test are being excluded after April 24, 2025, when Medicare payments for that test stopped from Novitas, removing an important reimbursement stream. Its business remains highly exposed to government and commercial reimbursement decisions, which can compress pricing and create volatility in revenue recognition, while adoption risk from physicians and payers could slow uptake of new tests. Competitive pressure, development-stage execution risk, and the industry’s tendency to operate at losses further raise the possibility that Castle may need additional capital without a clear guarantee it will be available.