Herbalife shares rally as some investors go long Herbalife, the Los Angeles-based multilevel marketing firm locked in a battle with New York hedge fund manager Bill Ackman, are rallying for a third straight day. The company's stock was up $1.90, or 6.7%, to $30.20 in midday Friday trading on Wall Street. The shares are now up 16% since their Christmas Eve closing price Monday. Herbalife's bump follows a four-day plunge of about 40% that began after Ackman branded the company a pyramid scheme and revealed he was betting against, or shorting, the stock. Other hedge fund managers are jumping into the battle, too. Whitney Tilson, who runs T2 Partners, disclosed he too was shorting Herbalife. But some are going long on Herbalife, which has said it will speed up a share buyback in the face of Ackman's onslaught. John Hempton, chief investment officer of hedge fund Bronte Capital, said on his blog he went long on Herbalife on Christmas Eve. "I am utterly convinced by everything in Bill Ackman's presentation except the final conclusion -- that Herbalife's stock will collapse," Hempton wrote, in comments earlier cited by the Wall Street Journal. "I suspect that Herbalife is so profitable and so powerful they will see Mr. Ackman's attack off - and the easiest way to do that is to buy back stock (and make the stock go up)," he added. The buyback may not be enough to help the stock recover, however. "The stock is down because the market apparently takes seriously the questions about the viability of the business," Lev Janashvili of GMI Ratings wrote in an e-mail to The Times. Unless the company credibly rebuts Ackman's thesis, the share repurchase will remain a largely symbolic gesture. Earlier this week, the New York Stock Exchange imposed restrictions on short sales of Herbalife's stock after its sharp decline. Those restrictions were lifted Thursday. Herbalife has scheduled a Jan. 10 meeting in New York to reassure analysts and investors.