BOSTON ( TheStreet ) -- Four questions for investors to ponder in the wake of Biogen's ( BIIB ) blow-up : 1. Will Biogen buy itself back into investors' good graces? With $4.5 billion in cash and the ability to double or triple that amount by assuming relatively cheap debt, Biogen has the balance sheet to make acquisitions. Buying quality assets or an entire company is a good way of mending fences with investors. Celgene ( CELG ), Alexion Pharmaceuticals ( ALXN ) and Abbvie ( ABBV ) have all been rewarded with higher stock prices after making deals this year. Isis Pharmaceuticals ( ISIS ) might be the most obvious Biogen takeout target given its existing partnership, but is it the smart move? Biogen is getting dinged lately, in part because investor confidence in its existing late-stage pipeline -- aducanumab and anti-LINGO -- is shaken.