The collapse of Valeant, as told by its stock chart

Bill Ackman has officially quit Valeant Pharmaceuticals.

The founder of hedge fund Pershing Square on Monday sold his investment in the company and will step down from the board. Valeant's shares fell as much as 10% after-hours.

The former stock market darling's stock has been falling consistently since September 2015 after the company began to face scrutiny over its pricing strategy, as well as its ties to a specialty pharmacy called Philidor. Its stock is down 95% since September 18, 2015.

Here's a timeline of what's happened to Valeant's shares since September 2015:

Business Insider/Andy Kiersz, data from Bloomberg