Start here if you're new
what it is
Castle sells genomic tests that help doctors decide how aggressive a cancer or disease case really is.
how it gets paid
Last year Castle Biosciences made $344M in revenue. DecisionDx-Melanoma was the main engine at $134M, or 39% of sales.
why it's growing
Revenue grew 3.7% last year. Quarterly history shows EPS improving from -$0.10 in Q4 FY2023 to $0.32 in Q4 FY2024.
what just happened
The clean takeaway is the business reached $0.32 in Q4 FY2024 EPS, but the reported revenue and recent EPS figures are messy across sources.
At a glance
B balance sheet — gets the job done, barely
20/100 earnings predictability — expect surprises
4.0% return on capital — nothing to write home about
$0.62 fy2024 eps est
$2B fy2026 rev est
xvary composite: 54/100 — below average
What they do
Castle sells genomic tests that help doctors decide how aggressive a cancer or disease case really is.
Doctors do not buy this because genomics sounds fancy. They buy it because a wrong cancer call is worse than a lab bill. At $344 million of annual revenue, Castle already sits in real clinic workflow, and once your doctor trusts one report, reordering is easier than guessing twice.
How they make money
$344M
annual revenue · their business grew +3.7% last year
DecisionDx-Melanoma
$134M
TissueCypher
$69M
DecisionDx-SCC
$52M
IDgenetix
$48M
Other tests and services
$41M
The products that matter
skin cancer risk stratification
DecisionDx-Melanoma
core portfolio driver
It sits inside the core test base that helped push report volume up 37% in 2025. That tells you physicians are using the platform, even if pricing is doing less of the work.
volume engine
Barrett's esophagus risk test
TissueCypher
inside $344.2M revenue
This test is part of a business that produced $344.2M of revenue in 2025 and still posted a -3.6% net margin. Adoption matters, but monetization matters more.
clinical expansion bet
newer test portfolio
Pipeline and newer launches
~$34M · ~10% of sales
The newer bucket is only about 10% of revenue, or roughly $34M in this snapshot. It is small today, but it is where incremental growth has to come from if the core business matures.
next leg of growth
Key numbers
$0.62
fy2024 eps est
$2B
fy2026 rev est
n/a
trailing p/e
n/a
dividend yield
Financial health
B
strength
- balance sheet grade B — adequate — nothing special
- risk rank 2 — safer than 80% of stocks
- price stability 5 / 100
- long-term debt $36M (4% of capital)
B — functional but not a standout on the balance sheet.
Total return vs. market
Return history isn't available for CSTL right now.
source: institutional data · return history unavailable
What just happened
missed estimates
The clean takeaway is the business reached $0.32 in Q4 FY2024 EPS, but the reported revenue and recent EPS figures are messy across sources.
Quarterly history shows EPS improving from -$0.10 in Q4 FY2023 to $0.32 in Q4 FY2024. EDGAR also shows a latest quarter at $257 million of revenue and EPS of -$0.76, which conflicts with other supplied figures.
$257M
revenue
$0.32
eps
n/a
n/a
the number that mattered
The most important number is FY2024 EPS of $0.62, because it marks the shift from annual losses to annual profit.
source: SEC filings and company earnings data, 2026
Get this snapshot in your inbox
This page, delivered free — plus weekly updates when the numbers change. plain english, no spam.
weekly updates
earnings alerts
plain english
no spam
What could go wrong
the #1 risk is reimbursement and regulation for lab-developed cancer tests.
med
Reimbursement and LDT regulation
Castle depends on physicians ordering reimbursed molecular tests. If lab-developed test oversight tightens or reimbursement weakens, the pressure lands on the core revenue engine fast.
The current page already flags $52M–$86M of revenue as potentially exposed.
med
Price per test keeps slipping
Core report volume climbed 37%, but 2025 revenue only rose 4%. That gap suggests reimbursement mix or realized pricing is doing the opposite of helping margins.
If that pattern holds, a business guiding to $340M–$350M in 2026 stays stuck chasing scale without profit.
med
Dilution becomes part of the story
The proposed underwritten common stock offering is a reminder that growth has not fully self-funded. That is a normal biotech-adjacent move. It is still dilution for you.
With the stock valued at roughly $760M, new shares are not a footnote.
A company with $344.2M of revenue, a -3.6% net margin, and near-flat guidance does not have much room for execution mistakes.
source: institutional data · regulatory filings · risk analysis
Pay attention to
guidance
2026 revenue has to do more than stall
Management guided to $340M–$350M after posting $344.2M in 2025. If the range stays this tight, the market will keep asking where the leverage is.
capital
Watch the public offering terms
A proposed common-stock raise can change the near-term valuation math quickly. Price, size, and use of proceeds all matter.
catalyst
DecisionDx data at SSO 2026
More clinical data can help physician confidence and guideline traction. That is useful. It still needs to show up in revenue quality next.
economics
Track revenue per report, not just report growth
The business already proved it can ship more reports. The number that matters now is whether each additional report turns into better dollars and better margin.
Analyst rankings
earnings predictability
20 / 100
Low predictability means quarterly numbers can move around more than you want. In human-speak, analysts do not see a smooth earnings story here.
risk rank
2
This measure says the company is safer than many stocks on balance-sheet factors. It does not mean the business model is proven.
source: institutional data
Institutional activity
institutional ownership data for CSTL is being compiled.
source: institutional data
Price targets
3-5 year target range
n/a
n/a
$33
current price
n/a
target midpoint · n/a from current
Want the deeper analysis?
The full deep dive: dcf model, scenario analysis, competitive moat breakdown, and quarterly tracking — everything on this page, taken further.
see plans from $5/moThe deep dive