Connecting decision makers to a dynamic network of information, people and ideas, Bloomberg quickly and accurately delivers business and financial information, news and insight around the world. Bearish investors have piled on bets against a reinsurer started by hedge fund manager David Einhorn as the company’s losses climbed. Short interest on Greenlight Capital Re Ltd., or bets that the stock will drop, climbed to the highest since 2009, at 5.4 percent of shares outstanding, according to Dec. 15 data compiled by Bloomberg and Markit Ltd. Short sellers are also targeting Dan Loeb’s Third Point Reinsurance Ltd., holding 3...