Shane Dinneen, the architect of Pershing Square Capital Management's huge short bet against Herbalife, has left the hedge fund.
Dinneen, an analyst at the New York-based firm, did much of the original work on the $1 billion bet on Herbalife, which Pershing Square founder William Ackman has called a pyramid scheme. Since announcing the short, however, Herbalife's shares have rallied, costing Pershing Square hundreds of millions of dollars in paper losses.
Still, Ackman was effusive in his praise for Dinneen, who has worked at Pershing Square since 2008.
"As Shane is one of the most talented investment analysts I have ever worked with and someone I hold in high regard, I have done my best to convince him to stay with the firm," Ackman wrote. "Recently, he decided it was time for him to move on to areas of his own interest outside of activist investing."
It's not clear what Dinneen's plans are.
Dinneen's involvement with the Herbalife short had disappeared in the past year, Ackman wrote, as Pershing Square's legal team took the lead. Ackman said that he remains "convinced that the company has operated an illegal pyramid scheme since its founding" and that he is "encouraged by the recent regulatory developments concerning the company."
Dinneen's exit from Pershing Square follows the departure of one of the firm's chief adversaries from his firm. Analyst Tim Ramey, who has for years been bullish on Herbalife and who has taken a few swipes at Ackman, has left D.A. Davidson for Post Holdings, Herbalife's fourth-largest shareholder. It is thought that Ramey's move to Post could presage a buyout of Herbalife by that company—an outcome that would be disastrous for Ackman's—and Dinneen's—short bet.