FILE - This April 3, 2013file photo shows bitcoin tokens at 35-year-old software engineer Mike Caldwell's shop in Sandy, Utah. The price of bitcoin, the most widely used virtual currency, rose above US$ 10,000 on Wednesday for the first time, breaking a symbolic threshold in what has been a vertiginous ascent this year. (AP Photo/Rick Bowmer, file) Foto: Rick Bowmer