Buffett says owning IBM shares could prove a mistake: CNBC

Warren Buffett, chairman and chief executive of Berkshire Hathaway Inc, told CNBC on Monday the firm's ownership of IBM shares could prove a mistake and that he was buying more U.S. stocks overall since the end of last year. "We've owned stocks that we've lost money in," said Buffett, the world's third-richest person. Berkshire, which held an 8.59 percent stake in IBM as of Dec. 31, 2015, said in an annual shareholder letter on Saturday that it planned to keep that stake despite a $2.6-bill