Herbalife (NYSE:HLF) continues to be a battleground between investors and short-sellers, made more prominent by big-name hedge-fund managers Carl Icahn and Bill Ackman taking aggressive positions on opposing sides of the stock. Icahn was the front-runner initially, with shares of the stock gaining 145% in 2013, but Ackman may now be gaining traction after repeated calls for investigation into the company's sales practices, to uncover whether it is more of a pyramid scheme than a legitimate business.

And apparently, the Federal Trade Commission was listening. Shares of the company plunged 15% on the news that it will be investigated by the FTC, though shares have now rebounded to a loss of only around 6%. The company itself says that it welcomes the investigation and is confident that it is in compliance.

In this video, Motley Fool health-care analyst David Williamson looks at the ongoing drama in the battle over Herbalife, and tells investors why this is a fight he's staying out of.

)