Castle Biosciences, Inc. (CSTL)

NASDAQ

$34.43

$+1.29

(+3.89%)

Regular Market

Castle Biosciences, Inc. (CSTL) Live Price Chart

Last updated: ⁦2026-10-21 15:33:40⁩. Prices reflect the latest regular market data. Stock price data is sourced from Massive.

Summary

Castle Biosciences, Inc. (CSTL) operates in the SERVICES-MEDICAL LABORATORIES sector and is listed on NASDAQ. The stock is currently priced at $34.43, with a market capitalization of $982.62M and a P/E ratio of --. Over the past 52 weeks, its price has ranged from $17.72 to $44.28. This page covers its latest market performance, valuation, price trends and company information.

Key Market Data

Market Cap	$982.62M
Open	$33.15
Day's High	$107.69
Day's Low	$2.26
Previous Close	$33.15
Volume	82.15K
Average Volume	405.21K
P/E Ratio	--
52-Week High	$44.28
52-Week Low	$17.72
Dividend Yield	--
Earnings Date	--

Castle Biosciences, Inc. (CSTL) Stock Price Today

Castle Biosciences, Inc. (CSTL) is currently trading at $34.43 as of 2026-10-21 15:31:00, up 3.86% ($1.28) from the previous close of $33.15

During today's regular trading session, CSTL has traded between $2.26 and $107.69, with a trading volume of 82.15K shares. The current price is near the lower end of today's range.

Castle Biosciences, Inc. (CSTL) 7-Day Stock Price Change

Over the past seven days, Castle Biosciences, Inc. (CSTL) moved from $32.76 to $34.43, representing a gain of 5.10% ($1.67).

The stock traded between $31.67 and $34.67 during the period. The latest price is near the upper end of the 7-day range, indicating strong upward.

The average daily volume was 301.08 thousand shares, down versus the previous seven-day period, indicating lower trading activity.

CSTL 52-Week Price Position

Position in Range: 62.9%

52W Low$17.72

52W High$44.28

CSTL is currently trading at $34.43, placing it 62.9% of the way from its 52-week low of $17.72 to its 52-week high of $44.28. This percentage reflects the stock's relative position within its 52-week trading range, not its valuation or future performance.

What is Castle Biosciences, Inc. (CSTL)?

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.

Castle Biosciences, Inc. Information

Industry	SERVICES-MEDICAL LABORATORIES
Employees	1002
Exchange	NASDAQ
Company Website	https://www.castlebiosciences.com

How to Buy Castle Biosciences, Inc. (CSTL) Stock on MEXC

Eligible investors can buy real shares of Castle Biosciences, Inc. (CSTL) through MEXC RealStocks. Follow these three steps to open a RealStocks account, transfer USDT, and place a US stock order.

Step 1: Open and Verify Your RealStocks Account

Log in to the MEXC App, go to Trade → RealStocks, and select Open Account. Complete the required account-opening and identity verification process with MEXC's partner licensed broker.

Step 2: Transfer USDT to Your RealStocks Account

Go to Wallets → RealStocks and transfer USDT from your Spot Account to your RealStocks Account. RealStocks are quoted in USD, while account funding can be completed using USDT.

Step 3: Search for CSTL and Place Your Order

Open the RealStocks trading page and search for CSTL. Select a market or limit order, enter the price and quantity as required, review the order details, and submit your order. Once filled, the corresponding real shares will be held in your RealStocks Account.

Frequently Asked Questions (FAQ)

1.What is Castle Biosciences, Inc. (CSTL) stock price today?

Castle Biosciences, Inc. (CSTL) is currently trading at $ 34.43, up 3.86% ($1.28) from the previous close of $ 33.15. Intraday prices update in real time during regular trading hours.

2.Is CSTL stock going up or down today?

As of 2026-10-21 15:31:00, CSTL is trading at $ 34.43, up 3.86% ($1.28) from its previous close of $ 33.15. The stock has traded between $ 2.26 and $ 107.69 during today’s regular session. Past price movements do not guarantee future results.

3.What is CSTL pre-market price?

As of 2026-10-21 15:31:00, CSTL is trading at $ 33.37 in pre-market trading, up 0.65% ($0.22) from the previous close of $ 33.15. Pre-market prices reflect trading activity before the regular session opens and may experience lower liquidity and higher volatility.

4.What is CSTL after-hours price?

As of 2026-10-21 15:31:00, CSTL is trading at $ 33.16 in after-hours trading, up 0.02% ($0.01) from the regular-session close of $ 33.15. After-hours prices may differ from the regular session’s opening price due to lower liquidity and wider bid-ask spreads.

5.Is CSTL stock trading now?

CSTL trades on the NASDAQ exchange during regular hours, Monday through Friday, 9:30 AM to 4:00 PM ET, excluding public holidays. Pre-market and after-hours trading are also available through select brokers outside these hours.

6.Where does CSTL sit relative to its 52-week high and low?

Over the past 52 weeks, CSTL has traded between a low of $ 17.72 and a high of $ 44.28. At $ 34.43, the stock is positioned 62.9% of the way from its 52-week low to its 52-week high, providing context for its current price within the one-year trading range.

7.What sector is Castle Biosciences, Inc. in?

Castle Biosciences, Inc. (CSTL) operates in the SERVICES-MEDICAL LABORATORIES sector. Sector classification helps investors compare it with companies exposed to similar market trends and competitive conditions.

8.What is Castle Biosciences, Inc.'s market capitalization and where is it listed?

Castle Biosciences, Inc. is listed on the NASDAQ exchange with a market capitalization of $ 982.62M. Market cap reflects the total market value of all outstanding shares and is commonly used to classify stocks by size.

9.How is CSTL valued in terms of P/E ratio and EPS?

CSTL trades at a P/E ratio of --, based on trailing-twelve-month EPS of $ -0.64. P/E ratio compares the stock price to earnings per share and is a common starting point for assessing valuation relative to peers.

10.Does Castle Biosciences, Inc. pay a dividend?

Castle Biosciences, Inc. pays an indicated annual cash dividend of $ 0.00 per share, with a current dividend yield of 0.00% based on the latest share price. Dividend policies are subject to change at the board's discretion.