Biogen Inc. (BIIB): A Bull Case Theory

We came across a bullish thesis on Biogen Inc. on r/Valueinvesting subreddit by U/Lobyous. In this article, we will summarize the bulls’ thesis on BIIB. Biogen Inc.'s share was trading at $131.52 as of July 25^th. BIIB’s trailing and forward P/E were 13.00 and 8.85 respectively according to Yahoo Finance.

Biogen (BIIB) remains deeply unloved by the market, largely due to its missteps with the FDA on Alzheimer’s drug Aduhelm, yet it continues to generate substantial and durable cash flows from its existing portfolio, with visibility for at least the next 5–10 years. The company’s legacy blockbusters Tecfidera and Tysabri face erosion from generics, but overall revenue has proven more resilient than expected, while growth drivers like Leqembi are set to gain traction, potentially contributing over $5 billion in revenue over the next four years.

Management has sought to bolster its relatively thin pipeline through acquisitions, most notably Reata Pharmaceuticals and its drug Skyclarys, and now has six Phase III candidates, with at least two—Tofersen and Felzartamab—showing strong prospects to become blockbusters by 2030. Despite recent challenges, Biogen delivered $2.72 billion in 2024 free cash flow, equating to a compelling 16% yield at the current market cap, with even a conservative forecast—assuming a 3% annual revenue decline through 2030 and excluding any pipeline or acquisition upside—suggesting a 10% margin of safety.

Broader market conditions may also work in Biogen’s favor, as the healthcare sector trades at historically low valuations, and a shift in sentiment could re-rate the stock. Near-term catalysts include stronger Leqembi uptake and one to two solid quarters that could draw institutional investors back. With shares trading in the $115–$130 range, Biogen offers an asymmetric risk/reward profile, and at sub-$115 levels appears highly attractive given its durable cash flows, undervalued pipeline, and potential for sector-wide recovery.

Previously, we covered a bullish thesis on Gilead Sciences, Inc. (GILD) by Disruptive Analytics in February 2025, which highlighted resilience in profitability despite headwinds from the Inflation Reduction Act, currency impacts, and declining COVID sales. The company’s stock price has appreciated by approximately 11.64% since our coverage, as the thesis played out. The thesis still stands as Gilead’s fundamentals remain intact. u/Lobyous shares a similar view but emphasizes Biogen’s undervaluation and catalysts from Leqembi.

Biogen Inc. is not on our list of the 30 Most Popular Stocks Among Hedge Funds. As per our database, 52 hedge fund portfolios held BIIB at the end of the first quarter which was 52 in the previous quarter. While we acknowledge the potential of BIIB as an investment, we believe certain AI stocks offer greater upside potential and carry less downside risk. If you're looking for an extremely undervalued AI stock that also stands to benefit significantly from Trump-era tariffs and the onshoring trend, see our free report on the best short-term AI stock.

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Disclosure: None.