1. financing overhang removed.
2. no discount on the secondary which indicates huge demand for shares and the deal was oversubscribed.
3. this is a biotech company that is not profitable. the market already expects offerings to come periodically.
IMO #2 is the biggest reason for the pop today as funds that that didn't get a complete fill from the bankers yesterday would have bought in the open market today to take advantage of a liquidty event.