By Bret Kenwell Biogen stock is up almost 40% on Wednesday but is barely holding above a key level. Let’s look at the chart. Shares of Biogen (BIIB) – Get Biogen Inc. Report are exploding higher on Wednesday, up almost 40% on the day. The stock is soaring due to promising data from the company’s late-stage Alzheimer’s drug trial. According to Martin Baccardax at TheStreet, Biogen and “its Japan-based partner Eisai Co. Ltd. unveiled better-than-expected results from a late-stage study of their developing Alzheimer’s treatment.” This stock has put together some massive moves over the years in bo…