Heads I win, tails you lose… and then you lose some more. That seems to be the story surrounding Bill Ackman’s disastrous near $4 billion loss in Valeant Pharmaceuticals. Ackman’s pharmaceutical foray is mostly over after his hedge fund Pershing Square dumped all of its Valeant shares in mid-March at $11 apiece, or an over 90% loss, cementing one of Wall Street’s biggest-ever investment …