Hedge fund all-star David Einhorn posts his worst year ever, losing 34% in 2018 By: CNBC.com News January 02, 2019 at 08:56 AM EST Greenlight Capital's main fund lost 34 percent in 2018, the worst performance since David Einhorn started the firm in 1996. Read More >> Related Stocks: Amazon.com Apple Brighthouse Financial Inc General Motors Tesla Exploratin Services Inc Tesla, Inc.