BIIB PDUFA decision: a positive outcome, +1.5%

On October 29, 2019, Biogen Inc. reached its PDUFA decision. The result was a positive outcome, and the stock moved +1.5% in the window around the event. It had already run +20.7% in the 30 days into the catalyst — the kind of pre-event run-up that often precedes binary readouts.