# Castle Biosciences (CSTL) — Overview

CSTL · NASDAQ · Stock

Canonical page: https://www.lighthorse.io/tickers/cstl

## Price

Last close $33.71 on Oct 15, 2026. 52-week range $18.15 – $43.04.

## Company profile

Castle Biosciences Inc is a molecular diagnostics company. The group provides test solutions for the diagnosis and treatment of dermatologic cancers, Barrett's esophagus (BE), and uveal melanoma. The product portfolio of the company includes DecisionDx-Melanoma, a risk stratification gene expression profile (GEP) test; DecisionDx-SCC, a risk stratification test for cutaneous squamous cell carcinoma; MyPath Melanoma, a diagnostic GEP test for use in patients with difficult-to-diagnose melanocytic lesions; and TissueCypher, a test to predict future development of progression of high-grade dysplasia and/or esophageal cancer. The company derives revenues through the delivery of test reports for its molecular diagnostic tests.

## Frequently Asked Questions

### How do I buy stock in Castle Biosciences (CSTL)?

CSTL trades commission-free with a Light Horse Securities brokerage account — from the mobile app, the web at [Light Horse Dashboard](https://portal.lighthorse.io), the trading API, or an [AI agent connected over MCP](/instructions/ai/claude). The trade panel on this page places the order once you are signed in.

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