CSTL

MKT CAP:$719M

Castle Biosciences, Inc.

Market Cap

$719M

Healthcare·Medical - Diagnostics & Research·🇺🇸 United States·NASDAQ

Healthcare·Medical·🇺🇸·NASDAQ

Stock Price

$23.69-$14.85 (-38.53%)

Apr 23, 2026

Company Details

Castle Biosciences, Inc., a commercial-stage diagnostics company, focuses to provide diagnostic and prognostic testing services for dermatological cancers. Its lead product is DecisionDx-Melanoma, a multi-gene expression profile (GEP) test ...

CEO

Derek J. Maetzold

IPO Date

Jul 25, 2019

Website

castlebiosciences.com

Key Metrics TTM

Revenue

$344M

+3.7% YoY

Net Income

-$24M

EPS (Diluted)

-$0.85

Free Cash Flow

$28M

Revenue / Share

$11.74

Gross Margin

68.7%

Operating Margin

-12.4%

Net Margin

-7.0%

FCF Margin

8.2%

P/S

2.1x

P/E

—

Earnings Reports

Q1 2026

May 4, 2026

PENDING

FY 2025

Feb 26, 2026

$344M+3.7%EPS -$0.83

Q4 2025

Feb 26, 2026

$87M+0.8%EPS -$0.08

Q3 2025

Nov 3, 2025

$83M-3.2%EPS -$0.02

Q2 2025

Aug 4, 2025

$86M-0.9%EPS $0.15

Revenue & Profitability

Quarter	Revenue	Gross Profit	Operating Income
Q1 22	$27M	$21M	-$25M
Q2 22	$35M	$27M	-$24M
Q3 22	$37M	$28M	-$22M
Q4 22	$38M	$29M	-$23M
Q1 23	$42M	$32M	-$32M
Q2 23	$50M	$39M	-$21M
Q3 23	$61M	$50M	-$10M
Q4 23	$66M	$54M	-$6M
Q1 24	$73M	$59M	-$5M
Q2 24	$87M	$72M	$5M
Q3 24	$86M	$70M	$5M
Q4 24	$86M	$70M	$4M
Q1 25	$88M	$72M	-$28M
Q2 25	$86M	$69M	-$4M
Q3 25	$83M	$64M	-$7M
Q4 25	$87M	$32M	-$4M

Valuation

Quarter	P/S	P/E
Q1 22	7.3x	—
Q2 22	6.5x	—
Q3 22	5.8x	—
Q4 22	5.2x	—
Q1 23	4.7x	—
Q2 23	4.3x	—
Q3 23	3.7x	—
Q4 23	3.3x	—
Q1 24	2.9x	—
Q2 24	2.5x	—
Q3 24	2.3x	118.3x
Q4 24	2.2x	39.4x
Q1 25	2.1x	—
Q2 25	2.1x	—
Q3 25	2.1x	—
Q4 25	2.1x	—

Operating Cash Flow

Quarter	Operating CF	Free CF
Q1 22	-$21M	-$22M
Q2 22	-$9M	-$10M
Q3 22	-$5M	-$7M
Q4 22	-$6M	-$8M
Q1 23	-$25M	-$29M
Q2 23	-$4M	-$8M
Q3 23	$5M	$3M
Q4 23	$19M	$15M
Q1 24	-$7M	-$16M
Q2 24	$24M	$19M
Q3 24	$23M	$17M
Q4 24	$24M	$17M
Q1 25	-$6M	-$11M
Q2 25	$21M	$12M
Q3 25	$23M	$8M
Q4 25	$27M	$20M

Capital Expenditures

Quarter	CapEx
Q1 22	$402.0K
Q2 22	$1M
Q3 22	$2M
Q4 22	$2M
Q1 23	$3M
Q2 23	$4M
Q3 23	$2M
Q4 23	$4M
Q1 24	$9M
Q2 24	$5M
Q3 24	$6M
Q4 24	$8M
Q1 25	$5M
Q2 25	$9M
Q3 25	$15M
Q4 25	$7M

CapEx

OpEx vs Revenue Growth (YoY)

Quarter	Revenue Growth	OpEx Growth
Q1 22	+17.7%	+89.6%
Q2 22	+53.1%	+87.6%
Q3 22	+57.7%	+65.9%
Q4 22	+53.1%	+52.1%
Q1 23	+56.6%	+43.2%
Q2 23	+43.9%	+20.4%
Q3 23	+66.1%	+21.5%
Q4 23	+72.5%	+17.3%
Q1 24	+73.6%	+6.6%
Q2 24	+73.5%	+15.0%
Q3 24	+39.5%	+13.5%
Q4 24	+30.5%	+14.6%
Q1 25	+20.6%	+47.8%
Q2 25	-0.9%	+10.3%
Q3 25	-3.2%	+11.3%
Q4 25	+0.8%	+10.4%

Stock-Based Compensation

Quarter	SBC ($)	% of Revenue
Q1 22	$8M	31.4%
Q2 22	$9M	25.2%
Q3 22	$9M	24.8%
Q4 22	$10M	25.9%
Q1 23	$14M	32.2%
Q2 23	$13M	25.6%
Q3 23	$13M	21.2%
Q4 23	$12M	17.8%
Q1 24	$13M	17.4%
Q2 24	$13M	15.1%
Q3 24	$13M	15.2%
Q4 24	$11M	13.3%
Q1 25	$11M	12.7%
Q2 25	$11M	13.0%
Q3 25	$12M	14.6%
Q4 25	$11M	13.1%

OpEx Breakdown

Quarter	R&D	G&A	S&M	SG&A
Q1 22	$11M	$12M	$18M	—
Q2 22	$12M	$16M	$22M	—
Q3 22	$11M	$14M	$22M	—
Q4 22	$11M	—	—	$38M
Q1 23	$14M	$17M	$30M	—
Q2 23	$13M	$16M	$28M	—
Q3 23	$13M	$16M	$28M	—
Q4 23	$13M	$17M	$27M	—
Q1 24	$14M	$18M	$31M	—
Q2 24	$14M	$18M	$33M	—
Q3 24	$12M	$21M	$30M	—
Q4 24	$12M	$20M	$30M	—
Q1 25	$13M	$22M	$37M	—
Q2 25	$13M	$23M	$35M	—
Q3 25	$13M	$23M	$33M	—
Q4 25	$14M	—	—	$57M

Revenue Segments

Quarter	Dermatologic	Service, Other
Q1 22	$24M	$3M
Q2 22	$32M	$3M
Q3 22	$34M	$3M
Q4 22	$35M	$4M

War Chest

Quarter	Cash	Short-term Investments	Total
Q1 22	$309M	$0	$309M
Q2 22	$273M	$0	$273M
Q3 22	$134M	$132M	$266M
Q4 22	$123M	$136M	$259M
Q1 23	$115M	$117M	$232M
Q2 23	$96M	$130M	$226M
Q3 23	$91M	$139M	$230M
Q4 23	$99M	$144M	$243M
Q1 24	$83M	$156M	$239M
Q2 24	$86M	$174M	$260M
Q3 24	$95M	$185M	$280M
Q4 24	$120M	$173M	$293M
Q1 25	$90M	$185M	$275M
Q2 25	$82M	$194M	$276M
Q3 25	$86M	$202M	$288M
Q4 25	$117M	$183M	$300M

Shares Outstanding

Quarter	Shares (Diluted)	QoQ Change	YoY Change
Q1 22	25M	+0.4%	+2.1%
Q2 22	26M	+2.5%	+3.9%
Q3 22	26M	+1.0%	+4.1%
Q4 22	26M	+0.3%	+4.2%
Q1 23	27M	+0.8%	+4.7%
Q2 23	27M	+0.5%	+2.6%
Q3 23	27M	+0.4%	+2.0%
Q4 23	27M	+1.2%	+2.8%
Q1 24	27M	+1.3%	+3.3%
Q2 24	29M	+4.6%	+7.5%
Q3 24	29M	+2.3%	+9.6%
Q4 24	30M	+2.7%	+11.3%
Q1 25	29M	-5.3%	+4.1%
Q2 25	30M	+3.3%	+2.8%
Q3 25	29M	-1.6%	-1.1%
Q4 25	29M	+0.9%	-2.9%

Shares Outstanding

Revenue Per Employee

Period	Revenue/Employee	Employees
Q1 22	$77.8K	345
Q2 22	$101.0K	345
Q3 22	$107.3K	345
Q4 22	$70.6K	543
Q1 23	$77.4K	543
Q2 23	$92.3K	543
Q3 23	$113.2K	543
Q4 23	$108.4K	610
Q1 24	$119.6K	610
Q2 24	$142.6K	610
Q3 24	$140.6K	610
Q4 24	$113.4K	761
Q1 25	$115.6K	761
Q2 25	$113.3K	761
Q3 25	$109.1K	761
Q4 25	$98.5K	883

Revenue / Employee