What is Biogen Inc. worth?
With the base-case assumptions below, a discounted cash flow model on Biogen Inc.'s reported free cash flow gives $122.12 per share. The share price was $227.60 on September 25, 2026, 86% 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% | $70.28 | -69% |
| Base | -5.0% | 9.0% | $122.12 | -46% |
| Bull | 0.0% | 8.0% | $218.75 | -4% |
Sensitivity: base case value per share
| 1.5% | 2.0% | 2.5% | 3.0% | 3.5% | |
|---|---|---|---|---|---|
| 7.0% | $156.61 | $166.76 | $179.16 | $194.66 | $214.59 |
| 8.0% | $131.17 | $137.75 | $145.52 | $154.85 | $166.26 |
| 9.0% | $112.43 | $116.93 | $122.12 | $128.17 | $135.33 |
| 10.0% | $98.04 | $101.24 | $104.86 | $109.01 | $113.79 |
| 11.0% | $86.62 | $88.97 | $91.59 | $94.54 | $97.88 |
Where the presets come from
Base: years 1 to 5 grow at Biogen Inc.'s revenue growth rate over the last 5 fiscal years (-6.0% 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