Biogen has been an active stock. Photo: John Tlumacki/The Boston Globe via Getty Images
A lot of Biogen's value hinges on whether federal scientists and regulators will approve or reject its drug candidate for Alzheimer's.
Driving the news: The drug, called aducanumab, has attracted people like Warren Buffett to invest in Biogen's stock on the assumption the drug will score approval for a patient population that desperately seeks a treatment. But other wealthy investors, like Ray Dalio, have taken a less sanguine view and dumped Biogen completely.
By the numbers: Warren Buffett's Berkshire Hathaway hadn't owned any shares of Biogen until it bought 648,000 new shares in the last quarter of 2019, according to regulatory documents flagged by Meg Tirrell of CNBC.
- Buffett's not alone. Hedge fund managers Steve Cohen of Point72 Asset Management, Ken Griffin of Citadel, Brandon Haley of Holocene Advisors and Ensign Peak Advisors, an investment firm affiliated with the Mormon Church, all either increased or took new stakes in Biogen in the last quarter of the year.
Yes, but: Ray Dalio of Bridgewater Associates sold off all of its 237,000 Biogen shares, according to regulatory filings.
- Parnassus Investments and HealthCor Management likewise divested all of their Biogen stakes, while a handful of others significantly dialed back investments.
The big picture: The FDA is expected to review and rule on Biogen's application at some point this year. The recent stock trading around Biogen gives a glimpse at how much is riding on this drug, and how much uncertainty there is around approval.
Go deeper: Why there's skepticism around Biogen's Alzheimer's drug