Reuters
The Canadian drug company's stock plummeted in early trading after short-selling firm Citron Research published a report comparing it to Enron.
The shares fell more than 30%, before rebounding. It ended trading at around $118, a drop of 19% on the day.
That added to a sharp fall in the share price that began with government inquiries into the company's pricing and business model last month.
The share price performance over the past few months has put an end to a seeming inexorable rise in the company's share price.
It moved from $26.30 on October 22 2011 to a high of $262.50 in August this year. It closed today at $118.32.
Here is an explainer for the Valeant's story so far.