Herbalife (HLF) continued to fall in afternoon trading on Thursday, a day after reports surfaced of hedge fund manager and noted short seller Bill Ackman calling the company a "pyramid scheme." Ackman officially lined out his positions on Thursday at an event in New York. Herbalife's shares fell 10% to 33.50 in afternoon trade after plummeting 12% on Wednesday. At the Thursday event, Ackman described the marketer of weight loss products as a