Herbalife rallies as Ackman says he'll short it to the end of the earth

Bill Ackman
David Grogan | CNBC

Bill Ackman went on the attack against Herbalife today--and shares surged upward.

At the Robin Hood Investors Conference, Ackman said in an interview that he would take his campaign against the company "to the end of the earth."

At an investor conference last year, Ackman announced that he was shorting Herbalife's stock. He described the company as a "pyramid scheme." Other investors, including Carl Icahn and George Soros, subsequently bought large stakes in Herbalife.