BOSTON, Nov 3 (Reuters) - Billionaire investor William Ackman's Pershing Square Holdings portfolio has lost 19 percent this year after his bet on Valeant Pharmaceuticals International soured, turning one of last year's biggest winners into one of this year's most prominent losers.
Pershing Square Holdings lost 7.3 percent in October, the firm, which invests roughly $16 billion for state pension funds, endowments and wealthy investors said on a Web site. The trouble was largely related to a 47 percent tumble in the stock of Valeant, a drug company Ackman added to his concentrated portfolio earlier this year.
But another one of Ackman's big bets on Platform Specialty Products also soured when it lost roughly 20 percent in the last month.
Last year Pershing Square Holdings gained 40 percent.
Reporting by Svea Herbst-Bayliss