Every single upstart biotech I have followed or owned has had the same bull/bear battles. Saw it in Medimmune, GILD, CELG, ONXX along with many more and all of the aforementioned turned out to be GIGANTIC winners.
Do your DD as best you can in trying to figure out the equation. As for me, I am buying because I see a smart man like Mr. Kovner taking a position, regardless of how small of an investment it is for him. Could he write off the loss if he is wrong? Sure he can but I guarantee that he would rather pay the capital gains on a nice winner.