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StockVS

NASDAQ · Diagnostics & Research · USD

Castle Biosciences, Inc. (CSTL) Stock Analysis

Castle Biosciences, Inc. (CSTL) is a Diagnostics & Research stock listed on NASDAQ and quoted in US Dollar.

Last Updated: October 21, 2026

CSTL

$34.37

+$1.22 (+3.68%)

Oct 21, 2026 · Market close

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Price History

Hover for the daily close. The dotted line marks the period open.

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CSTL Key Statistics

As of Oct 21, 2026
Trading
Open
$33.15
Previous Close
$33.15
Day's Range
32.93–34.72
52-Week Range
17.72–44.28
Volume
336.59K
BetaHow much the share price moves relative to the wider market. 1.0 moves in line with it; above 1.0 swings more, below 1.0 less.
0.95
Valuation
Market Cap
$1.05B
P/E Ratio
unprofitable
P/S ratioMarket value divided by annual revenue. Useful for companies that are not yet profitable, where a P/E cannot be calculated.
2.94
EPS (ttm)Profit attributable to each share over the last twelve months.
−0.64
Financials (FY)
Revenue (FY)
$344.23M+3.66%
Net Income (FY)
−$24.16M−232.41%
Profit marginThe share of revenue left as profit after all costs and taxes.
−5.43%
Shares OutstandingThe total number of shares held by all investors. Market value is this figure multiplied by the share price.
30.55M
1-Year Return
+46.88%
Dividend and dates
Earnings Date
November 5, 2026
Avg Volume
405.70K

Only metrics the company reports are shown. Data provided by Yahoo Finance via yfinance. Updated daily.

Key facts

As of October 21, 2026, CSTL closed at $34.37, +46.88% over 1 year.

Castle Biosciences, Inc. (CSTL) has a market capitalization of $1.05B.

In fiscal 2025, CSTL reported revenue of $344.23M.

CSTL Stock Return by Calendar Year

Castle Biosciences, Inc. (CSTL) return since Jul 2019: what $10,000 became

1 year
$10,000 $14,688
+46.88%
5 years
$10,000 $5,463
−45.37%
Since Jul 2019
$10,000 $16,061
+60.61%

If you had invested $10,000 in Castle Biosciences, Inc. (CSTL) at the close on July 25, 2019, the earliest close on record here, it would have been worth $16,061 at the close on October 21, 2026: +60.61% in total, +6.76% a year, over a partial period shorter than 10 years. A historical calculation from closing prices adjusted for splits and dividends, before fees and taxes.

Calendar-year returns computed from daily closing prices. Partial years are shown muted and marked with an asterisk.

YearReturn
2026 (partial year)−11.65%
2025+45.97%
2024+23.49%
2023−8.33%
2022−45.09%
2021−36.16%
2020+95.37%
2019 (partial year)+60.61%

As of October 21, 2026.

CSTL Revenue and Earnings by Fiscal Year

FY ends December
Fiscal yearRevenueNet incomeNet margin
2025$344.23M−$24.16M−7.0%
2024$332.07M$18.25M5.5%
2023$219.79M−$57.47M−26.1%
2022$137.04M−$67.14M−49.0%
Fiscal yearRevenueGross profitOperating incomeNet incomeNet margin
2025$344.23M$273.20M−$42.81M−$24.16M−7.0%
2024$332.07M$271.86M$8.67M$18.25M5.5%
2023$219.79M$174.81M−$67.98M−$57.47M−26.1%
2022$137.04M$105.03M−$91.14M−$67.14M−49.0%

Annual figures as reported, in the company's reporting currency. As of December 31, 2025.

CSTL Valuation vs Diagnostics & Research Median

Median of 45 stocks
MetricCSTLDiagnostics & Research medianvs median
P/S ratio2.945.2344% below
Profit margin−5.43%−0.93%4.5 pts below

Medians across 45 Diagnostics & Research stocks that report the metric. Medians, not averages, so one outlier cannot move them. As of October 21, 2026.

Recent News

All 15 articles ↓

News provided by third-party sources. Not financial advice.

Analysis

Data-derived

Company Overview

Castle Biosciences, Inc. (CSTL) is capitalised at $1.05B on the latest close. The company sits in the Healthcare sector, in the Diagnostics & Research industry. Headcount on file is 1,002.

CSTL last closed at $34.37 on October 21, 2026. That is +$1.22 (+3.68%) against the previous close. Over the past 52 weeks the price has ranged from $17.72 to $44.28. The latest close sits 93.94% above that 52-week low.

Financial Health

The most recent full year on file, fiscal 2025, shows revenue of $344.23M. That is +3.66% against the prior fiscal year, when revenue was $332.07M. The same year closed with a net loss of $24.16M. The reported profit margin is −5.43%. That is 4.5 percentage points below the Diagnostics & Research median of −0.93%. Earnings per share on a trailing basis come to −0.64.

Across the 4 fiscal years on file, revenue moves from $137.04M in 2022 to $344.23M in 2025. Of those 4 years, 1 report positive net income.

Valuation Assessment

The record shows negative trailing earnings, so no price-to-earnings ratio is published. Measured against sales, the shares trade at 2.94 times revenue. On price-to-sales that is 43.77% below the Diagnostics & Research median of 5.23. 45 Diagnostics & Research companies report these metrics, and the medians quoted come from that group.

Over the trailing twelve months the total return is +46.88%. Measured over 5 years, that is −11.39% a year compounded. The reported beta is 0.95. Daily returns over the trailing 7 years annualize to a volatility of 73.02%.

Growth & Income

The record shows no dividend for CSTL.

Across the complete calendar years on file, 2020 returned +95.37% and 2022 returned −45.09%. Of the 6 complete calendar years on file, 3 finished higher. So far in 2026 the total return is −11.65%.

Peer Comparison

Castle Biosciences, Inc. (CSTL) operates in the Diagnostics & Research industry. Here is how it compares to its closest peers by market capitalization:

Company Ticker Market Cap P/E Ratio
Castle Biosciences, Inc. CSTL $1.05B —
Thermo Fisher Scientific Inc. TMO $256.61B 37.4
Danaher Corporation DHR $164.40B 41.7
Natera, Inc. NTRA $59.59B —

The Diagnostics & Research industry average P/E ratio is 37.6x. Castle Biosciences, Inc. has no P/E ratio because it is not currently profitable.

Every figure above is read from this page's own data on each daily rebuild. Informational only, not financial advice. As of October 21, 2026.

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About Castle Biosciences, Inc.

Castle Biosciences, Inc., a molecular diagnostics company, provides test solutions for the diagnosis and treatment of dermatologic cancers, Barrett's esophagus (BE), atopic dermatitis (AD), and uveal melanoma. The company offers DecisionDx-Melanoma, a risk stratification gene expression profile (GEP) test that predicts the likelihood of a positive sentinel lymph node and the risk of metastasis for patients with invasive cutaneous melanoma; TissueCypher, a risk stratification spatialomics test to predict future development of high-grade dysplasia and/or esophageal cancer in patients with non-dysplastic, indefinite dysplasia, and low-grade dysplasia BE; AdvanceAD-Tx, a non-invasive GEP test which is designed to guide systemic treatment selection for patients aged 12 years and older with moderateto-severe AD; DecisionDx-SCC, a GEP test for cutaneous squamous cell carcinoma; and MyPath Melanoma, a diagnostic GEP test for use in patients with difficult-to-diagnose melanocytic lesions. It also provides DecisionDx-UM, a risk stratification GEP test that predicts the risk of metastasis for patients with uveal melanoma. The company offers its products to dermatology and gastroenterology markets. The company was incorporated in 2007 and is headquartered in Friendswood, Texas.

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