MeritValue

CASTLE BIOSCIENCES INC

CSTLdata completeness 100%8 fiscal years on file

Data notes: no data for concept 'pretaxIncome'

The thesis, from the filings

CASTLE BIOSCIENCES INC earns about -8% on equity, below its ~9% cost of capital, but has diluted owners by 15% over 5 years — no moat visible in the numbers. The estimate methods put fair value between $20.68 and $22.15 a share.Whether it’s worth owning at today’s price is the last question — and yours to answer, below.

i. The business — what you’d actually own
FigureFY 2021FY 2022FY 2023FY 2024FY 2025
Revenue$94.1M1$137M2$219.8M3$332.1M3$344.2M3
Net income−$31.3M4−$67.1M5−$57.5M6$18.2M6−$24.2M6
Operating cash flow−$19M7−$41.7M8−$5.63M9$64.9M9$64.3M9
Capital expenditure$3.48M10$5.63M11$13.6M12$28.3M12$36M12
Free cash flow (derived)−$22.5M7−$47.3M8−$19.2M9$36.5M9$28.3M9
Total debt——$013$20M14$20.1M14
Cash & equivalents$329.6M15$122.9M16$98.8M17$119.7M18$116.7M18
Diluted shares25.1M26.1M26.8M29.3M29.0M

Superscripts are receipts. Each links to the SEC filing the number came from (full list at the bottom).

ii. Your slice — ownership made literal
If you owned
shares
Net assets behind them
$162.45
your share of equity
Profit it earned you last year
−$8.33
Free cash flow it threw off
$9.77
Debt you’d be carrying
$6.94

10 shares is a claim on $162.45 of net worth that earned you −$8.33 and generated $9.77 of cash last year, against $6.94 of debt.

iii. Is this a good business?
Moat signal · return on equity
-8% avg · 5y
FY21 -8%FY22 -17%FY23 -15%FY24 4%FY25 -5%

It earned about -8% on equity against a ~9% cost of capital — below the cost of funding. The numbers show no moat.

seeing a moat in the numbers →
Management signal · capital allocation
+15% shares · 5y

Share count is up 15% over 5 years — owners have been diluted. Worth asking what they got for it.

reading capital allocation →

Signals, not verdicts — read from the filings above. Numbers don’t prove a moat; they show its footprint. You decide.

iv. What it’s worth — engine v0.1.0

The 2 estimate methods that apply put fair value between $20.68 and $22.15 a share. They rest on different assumptions, so where they diverge is the story.

DCF · Growth Exit 10Y
$22.15
assumptions (10)
  • riskFreeRate4.7%
  • equityRiskPremium5.0%
  • beta100.0%
  • equityWeight85.0%
  • costOfDebtSpread1.5%
  • taxRate21.0%
  • terminalGrowth2.5%
  • projectionYears10
  • fcfGrowth5.0%
  • fcfBase$28.3M
DCF · Growth Exit 5Y
$20.68
assumptions (10)
  • riskFreeRate4.7%
  • equityRiskPremium5.0%
  • beta100.0%
  • equityWeight85.0%
  • costOfDebtSpread1.5%
  • taxRate21.0%
  • terminalGrowth2.5%
  • projectionYears5
  • fcfGrowth5.0%
  • fcfBase$28.3M
Earnings Power Value
not applicable
normalized (5y-median) earnings non-positive — EPV undefined
Graham Number
not applicable
diluted EPS missing or non-positive — Graham Number undefined

Different models answer different questions — which to trust when →

v. The price question — last, on purpose
Is today’s price fair?
See live price ↗
Type a price. The ledger answers.
Or set your own belief
FCF growth, next 5 years5.0%
Discount rate (WACC)8.93%
Terminal growth2.5%
At your growth, a share is worth $20.68
The three cases
Bear0.0%$17.3
Base5.0%$20.68
Bull10.0%$24.72

Bear/base/bull growth = 0% / filed history / history + 5pp. Type a price to see the return each case implies.

Default growth 5.0%= this company’s own filed history (median-to-median FCF CAGR, clamped 0–20%). Your adjustments are recorded anonymously. They become the “what do owners actually believe” dataset.

Sources — the receipts
  1. 10-K · period ending 2021-12-31 · accession 0001447362-23-000038 (RevenueFromContractWithCustomerExcludingAssessedTax)
  2. 10-K · period ending 2022-12-31 · accession 0001447362-25-000031 (RevenueFromContractWithCustomerExcludingAssessedTax)
  3. 10-K · period ending 2023-12-31 · accession 0001628280-26-012272 (RevenueFromContractWithCustomerExcludingAssessedTax)
  4. 10-K · period ending 2021-12-31 · accession 0001447362-23-000038 (NetIncomeLoss)
  5. 10-K · period ending 2022-12-31 · accession 0001447362-25-000031 (NetIncomeLoss)
  6. 10-K · period ending 2023-12-31 · accession 0001628280-26-012272 (NetIncomeLoss)
  7. 10-K · period ending 2021-12-31 · accession 0001447362-23-000038 (NetCashProvidedByUsedInOperatingActivities)
  8. 10-K · period ending 2022-12-31 · accession 0001447362-25-000031 (NetCashProvidedByUsedInOperatingActivities)
  9. 10-K · period ending 2023-12-31 · accession 0001628280-26-012272 (NetCashProvidedByUsedInOperatingActivities)
  10. 10-K · period ending 2021-12-31 · accession 0001447362-23-000038 (PaymentsToAcquirePropertyPlantAndEquipment)
  11. 10-K · period ending 2022-12-31 · accession 0001447362-25-000031 (PaymentsToAcquirePropertyPlantAndEquipment)
  12. 10-K · period ending 2023-12-31 · accession 0001628280-26-012272 (PaymentsToAcquirePropertyPlantAndEquipment)
  13. 10-K · period ending 2023-12-31 · accession 0001447362-25-000031 (LongTermDebtNoncurrent)
  14. 10-K · period ending 2024-12-31 · accession 0001628280-26-012272 (LongTermDebtNoncurrent)
  15. 10-K · period ending 2021-12-31 · accession 0001447362-23-000038 (CashAndCashEquivalentsAtCarryingValue)
  16. 10-K · period ending 2022-12-31 · accession 0001447362-24-000017 (CashAndCashEquivalentsAtCarryingValue)
  17. 10-K · period ending 2023-12-31 · accession 0001447362-25-000031 (CashAndCashEquivalentsAtCarryingValue)
  18. 10-K · period ending 2024-12-31 · accession 0001628280-26-012272 (CashAndCashEquivalentsAtCarryingValue)