Biogen Inc is a biopharmaceutical company. It is engaged in discovering, developing, manufacturing and delivering therapies to patients for the treatment of neurological, rare and autoimmune diseases. It has very strong fundamentals: Net Margin 43.8%, Return on Capital 138% and its relatively cheap traded at 12.3 x Price-to-Free-Cash-Flow.
This morning BIIB dropped by 27% at open. Despite the fact that its a great company with attractive valuation I would NOT buy it here. The move down off the top at 480.18 reached in March 2015 looks like a classic corrective (A)-(B)-(C) down structure. The final wave (C) down should stretch at least to 76.4% extension of the first leg down in wave (A) that bottomed at 223.02 in July 2016. When price gets to 192 or lower in a move down with a clear five wave structure I would be interested in buying that stock.