Below are five stocks owned by billionaire investors, each of which the investor involved has projected to double in price, or better: 1) Hertz (HTZ) - Billionaire Barry Rosenstein, head of the activist hedge fund Jana Partners, recently said at an investing conference that he believes Hertz shares could triple in price. Rosenstein said Hertz could buy back as much as 20 percent of its shares, which would double earnings per share and cause ...