More and larger M&A deals could boost public biopharmaceutical companies, so investors will watch closely to see if Pfizer's $14bn Medivation acquisition kicks off a widespread spending spree. Speculation about who'll be bought next is in full swing.

Two companies in the biopharma space began trading publicly this week, one to pay off debt, the other to fund an early-stage pipeline.

The biotech is shifting gears after clinical hold on its lead drug was unlikely to be lifted, but the early-stage candidate that it's placing its hopes on is raising red flags for analysts and investors.