barry - could be any of these. If b, it won't work. The pps will sink like a stone. With biotechs, anything negative and everyone scurries away.
Buying a few puts as insurance is probably a good thing.
That said, bad news would probably be released before market opens. In addition, Berger has been pushing this conference so long and so hard, it is difficult to imagine he is not going to look good.
Of course, all, jmo.