What is Castle Biosciences Inc worth?
With the base-case assumptions below, a discounted cash flow model on Castle Biosciences Inc's reported free cash flow gives $34.08 per share. The share price was $35.81 on September 25, 2026, 5% above that value.
Inputs from the filings
Three sets of assumptions
| Case | Growth yrs 1-5 | Discount rate | Value per share | Value vs price |
|---|---|---|---|---|
| Bear | 10.0% | 10.0% | $21.41 | -40% |
| Base | 15.0% | 9.0% | $34.08 | -5% |
| Bull | 20.0% | 8.0% | $57.67 | +61% |
Sensitivity: base case value per share
| 1.5% | 2.0% | 2.5% | 3.0% | 3.5% | |
|---|---|---|---|---|---|
| 7.0% | $43.67 | $46.67 | $50.32 | $54.89 | $60.77 |
| 8.0% | $36.47 | $38.41 | $40.70 | $43.45 | $46.81 |
| 9.0% | $31.23 | $32.55 | $34.08 | $35.87 | $37.98 |
| 10.0% | $27.25 | $28.19 | $29.26 | $30.48 | $31.89 |
| 11.0% | $24.14 | $24.83 | $25.60 | $26.47 | $27.46 |
Where the presets come from
Base: years 1 to 5 grow at Castle Biosciences Inc's revenue growth rate over the last 5 fiscal years (40.6% a year), held between -5% and 15%. Years 6 to 10 grow halfway between that and the long-run rate of 2.5%. Future cash is discounted at 9% a year.
Bear: 5 points less growth, 2% long-run growth, 10% discount rate. Bull: 5 points more growth (at most 25%), 3% long-run growth, 8% discount rate.
Value per share = (present value of 10 years of free cash flow + present value of everything after + cash - debt) / diluted shares.
This is a model run on assumptions, not a recommendation or a price target. Small changes in the discount rate or growth move the result a lot, as the table above shows. Change them yourself in the calculator.
Adjust the assumptions
Move the sliders for growth, long-run growth and discount rate, or switch to average free cash flow, and see the value per share change.
Adjust the assumptions