BOSTON, Jan 5 (Reuters) - Billionaire investor William Ackman's Pershing Square Holdings hedge fund ended 2015 with a 20.5 percent loss after Valeant Pharmaceuticals, a top holding, has battered in the second half of the year.
The fund, one of several portfolios run by the firm, ended December nearly flat with a 0.3 percent gain for the month, Pershing Square, one of the industry's most closely watched hedge funds, told investors in an update.
News of the sharp drop wasn't a surprise since Ackman told investors two weeks ago that the year would likely end up being the worst in the firm's 11 year history. But it illustrates just how volatile the activist investor's returns can be after he scored a 40 percent gain in 2014 when he ranked among the industry's best performers. (Reporting by Svea Herbst-Bayliss)