Here's Who May Have Been Crushed in Biogen's $18 Billion Plunge

Several large hedge funds are likely reeling Thursday after a failed study in Alzheimer’s disease erased more than $18 billion from Biogen Inc.’s market value.

While Biogen’s drug had been viewed as a high-risk, high-reward gamble for the drugmaker and its investors, the failed futility analysis came a year before results were expected from the late-stage trial. That 2020 event was seen as a binary catalyst for the stock, and it’s unlikely that shareholders made big changes to their disclosed positions in the first few months of this year.