Biogen (BIIB)
Health Care · $37.0B market cap · SEC CIK 0000875045
ahead of 10% of the S&P 500 · #55 of 59 in Health Care
Next reports on Feb 4, 2027, after the close, with analysts expecting $2.81 in earnings per share.
52-week range $151.83 to $261.00. 3% below its 52-week high and 67% above its low.
The case for BIIB
- Generated $2.1B of free cash flow in FY2025, 21% of revenue.
- Gross margin of 74% absorbs cost shocks.
- Moves less than the market (beta 0.07).
- Within 3% of its 52-week high: the trend is up.
- Up 63.9% over the past year.
The case against
- Expensive for its growth: 106.6× earnings, where 0% a year of growth would justify about 8×.
- Earnings per share down 78.7%.
- Return on equity of only 2%.
- Revenue has shrunk 6.0% a year over five years.
- Net margin of 3.4% leaves very little room for error.
- Revenue grew only 2.3%, roughly the pace of inflation.
What the score is made of
Each factor is half a curve over reported figures and half a rank among the other Health Care companies (momentum is judged against fixed thresholds only), and the five are blended by weight. The score is where that blend places it in the S&P 500. It describes the last filing and the current price. It is not a forecast.
| Valuewhat you pay for the earnings and cash, against the growth you get | 14 |
|---|---|
| Growthhow fast revenue and earnings are moving, this year and over five | 9 |
| Profitabilityhow much of the revenue becomes profit, and how much of that is cash | 37 |
| Momentumhow the price has behaved lately | 90 |
| Stabilityhow violently it moves, what it owes and what it pays you | 57 |
- Each factor except momentum is half fixed thresholds, half rank among the 59 Health Care companies.
The financials
Revenue growth
Is the business growing? Slowly
| Last 12 months | +2.3% |
|---|---|
| Over 5 years | −6.0% a year |
| FY2025 revenue | $9.9B (+2%) |
Free cash flow
Is it generating real cash? Yes, plenty
| FY2025 free cash flow | $2.1B |
|---|---|
| Of revenue | 21% |
| Of profit | 159% |
Profit margins
Is profitability improving? No, slipping
| Gross margin | 74% |
|---|---|
| Operating margin | 6% |
| Net margin, FY24 → FY25 → now | 16.9% → 13.1% → 3.4% |
Debt vs. cash
Is the balance sheet healthy? Yes, the debt is manageable
| Cash | $3.0B |
|---|---|
| Long-term debt | $6.3B |
| Net debt | $3.3B |
| Years to repay | 2.9 yrs |
Valuation
Is the stock price reasonable? No, expensive
| P/E | 106.6× |
|---|---|
| Fair P/E for its growth | 8× |
| P/FCF | 18.1× |
| Forward P/E | 16.5× |
| EV / EBITDA | 35.9× |
At 106.6× earnings it trades well above the 8× that 0% a year of growth would justify. At 18.1× free cash flow it trades well above that same mark.
The financials, five years deep
Pulled from Biogen's XBRL filings on SEC EDGAR. Italic rows are worked out from the others.
| FY2025 | FY2024 | FY2023 | FY2022 | FY2021 | |
|---|---|---|---|---|---|
| Revenue growth | |||||
| Revenue | $9.9B | $9.7B | $9.8B | $10.2B | $11.0B |
| Change on the year | +2% | −2% | −3% | −7% | — |
| Free cash flow | |||||
| Free cash flow | $2.1B | $2.7B | $1.3B | $1.1B | $3.4B |
| Of revenue | 21% | 28% | 13% | 11% | 31% |
| Profit margins | |||||
| Operating margin | — | — | — | — | 25.9% |
| Net margin | 13.1% | 16.9% | 11.8% | 29.9% | 14.2% |
| Debt vs. cash | |||||
| Cash | $3.0B | $2.4B | $1.0B | $3.4B | $2.3B |
| Long-term debt | $6.3B | $6.3B | $6.9B | $6.3B | $6.3B |
| Net cash (debt) | −$3.3B | −$3.9B | −$5.9B | −$2.9B | −$4.0B |
What Biogen says it does
OVERVIEW Biogen is a global biopharmaceutical company focused on discovering, developing and delivering innovative therapies for people living with serious and complex diseases. We have a broad portfolio of medicines to treat MS, have introduced the first approved treatment for SMA, co-developed treatments to address a defining pathology of Alzheimer’s disease and launched the first approved treatment to target a genetic cause of ALS. We market the first and only drug approved in the U.S., the E.U. and certain international markets for the treatment of FA in adults and adolescents aged 16 years and older. We are focused on advancing our pipeline in neurology, specialized immunology and rare diseases. We support our drug discovery and development efforts through internal research and development programs, external collaborations and acquisitions. Our marketed products include VUMERITY, TYSABRI, TECFIDERA, AVONEX and PLEGRIDY for the…