Valeant's downfall — illustrated by its stock chart (VRX)

Bill Ackman has officially quit Valeant Pharmaceuticals.
The founder of the hedge fund Pershing Square on Monday sold his investment in the company and announced his plan to step down from the board. Valeant's shares fell by as much as 10% after-hour on Monday.
Once a stock market darling, Valeant has been falling since September 2015 after the company began to face scrutiny over its pricing strategy and its use of a secret specialty pharmacy called Philidor. When Philidor's existence — wh