Bill Ackman buys 2 million shares of Valeant after it craters on accusations of being the next Enron

Hedge fund titan Bill Ackman purchased 2 million more shares of Valeant Pharmaceuticals Wednesday amid the stock's decline, CNBC's Scott Wapner reports.

The stock was last down 15.7% at about $123.69 per share.

The Canadian drug company's stock cratered after short-selling-firm Citron Research published a report comparing it to Enron. Its share price had fallen as low as around $89 before rebounding.

Ackman told CNBC that he has not sold a single share.

With the increased position, Ackman's Pershing Square Capital Management now owns 21,473,933 shares of Valeant.

Ackman publicly disclosed his position in Valeant March 17, when the share price was $200 per share. At that share price, the position was worth $3.9 billion.

His stake is now worth about $2.5 billion with his increased stake.