Top U.S. hedge fund managers circled General Motors after the automaker’s shares fell 15.8 percent during the first quarter, with David Tepper’s Appaloosa Management and John Paulson’s Paulson Management LP increasing stakes. Paulson Management increased its exposure in GM by 114.9 percent to 4.0 million shares and Appaloosa boosted its GM share figure by 58.7 percent to 7.9 million shares, regulatory filings showed on Thursday. Not every big investor remained positive on GM. Barry Rosenstein’s Jana Partners sold nearly all of its GM stake, cutting its holding by about 8 million shares to just 7,100 shares.