Greenlight Capital CEO David Einhorn, during his presentation at the annual Value Investing Congress event in New York City, discussed a short position in Chipotle Mexican Grill (CMG). Einhorn said the company is under significant competitive pressure, specifically from new menu items at Yum! Brands' (YUM) Taco Bell. Einhorn reiterated his short position in Green Mountain Coffee (GMCR), citing patent expirations and competitive pressures. Einhorn recommended long positions in General Motors (GM), which he thinks is undervalued because of an overreaction to sluggishness in Europe, and Cigna (CI), which Einhorn believes is trading for a discount compared to peers that themselves are undervalued. Notably, Einhorn said at the outset of the event that he would not be discussing Herbalife (HLF), which was widely speculated to be one of his short sale targets. Shares of Herbalife advanced during his time presenting, as did shares of lululemon (LULU), which Einhorn did not mention during the event though rumors had circulated that he might speak about it negatively. In early afternoon trading, shares of Chipotle sank 5.73% to $298.00, while GM advanced 1.69% to $23.48 and Cigna rose 1.23% to $48.68.