Biogen (BIIB) Stock News Today (Dec. 22, 2025): QALSODY Data, Nasdaq-100 Exit, and Analyst Forecasts
Biogen Inc. (NASDAQ: BIIB) is in focus on Monday, December 22, 2025—a day that combines company-specific clinical headlines with a major index event for the stock. Investors are weighing fresh long‑term data for QALSODY (tofersen) in a rare genetic form of ALS, Biogen’s public statement honoring co‑founder Charles Weissmann, and the market mechanics of Biogen’s removal from the Nasdaq‑100, which becomes effective today. At the same time, Wall Street’s outlook remains mixed but active: recent analyst notes span “Reduce/Hold” to “Outperform” with price targets stretching from the low‑$140s to above $200, reflecting a debate over how quickly newer products—especially Leqembi