BOSTON (Reuters) - Hedge fund Greenlight Capital said it sold its position in carmaker General Motors, saying the company's forecast for 2020 was worse than the hedge fund had expected. "General Motors was a disappointment," the firm wrote to investors in a letter seen by Reuters. "We sold our stock." During the five years that Greenlight owned shares in the carmaker, the hedge fund earned an internal rate of return of 9.6%, the letter said.