AP Images
Shares of the multi-level marketer were last trading down 14.44%, or down $8.07, at around $47.83 per share.
Also, on Friday, Herbalife agreed to pay $15 million to settle a class action lawsuit filed by a former distributor who claimed the company was running a "pyramid scheme."
For nearly 23 months, hedge fund manager Bill Ackman, who runs Pershing Square Capital, has been crusading against Herbalife on the same allegation.
In December 2012, Ackman gave a 342-slide presentation publicly declaring that he was short $1 billion worth of Herbalife shares. It's Ackman's contention that the company operates as a "pyramid scheme" that targets poor people. His investment thesis in predicated on regulators, specifically the Federal Trade Commission, shutting the company down. (The FTC opened an investigation into the company back in March.)
What's more is after Ackman's initial presentation, a number of other fund managers, most notably his long-time rival Carl Icahn, piled on by going long the stock.
Here's a 5-day chart:
Yahoo! Finance
Here's how the stock has performed since Ackman made his short public:
Yahoo! Finance