thealias, if people would do that then MOST of the time they would be shaken out of EVERY good investment, not specifically PPHM.
Look at ALL the biotech that have had a sudden price jump up. All were at some point, and very often quite close BEFORE the jump, having a PPS that would make shareholders leave that investment if they would ask you suggested question.
Then of course that is how Dart, Buffet and others make money. Someone must pay the price and if you paid on average 1.50$ for PPHM and leave at 0.40$ then one is contributing 1.10$ per share to that system.
That is why they say you don't have ANY profit until you sell (because in ONE day the PPS can drop death) and of course the other way around why you have no losses until you sell (because the PPS can in ONE day jump up).
And we have plenty of examples out there in BOTH directions.