02 May 2016 Einhorn's Greenlight Buys Yelp, Takes Wager on Natural Gas ( Portfolio ) “The stock has suffered due to missed expectations and anxiety about an upcoming negative documentary," the New York-based hedge fund wrote in the letter obtained by Bloomberg. Yelp shares, which had fallen 25 percent this year, jumped 5.2 percent in after-hours trading to $22.62 at 5:12 p.m. in New York after Bloomberg reported the news.