> Basically, a person like Ackman and some friends could (in theory) bid up a stock 1000%, mark it there at the end of the month or year (or whenever they account for the performance fee), take their performance fee on that mark, and let it crash. In fact, doesn't that sound a lot like Valiant?

How much do you think Ackman lost in personal money on Valeant? You don't think it's much more than the performance fees that he earned from it?