Bitcoin heading over $10,000 in six to 10 months, former Fortress hedge fund manager says Bitcoin has surged this year, up to $4874 on Tuesday, and Michael Novogratz sees it heading over $10,000. Novogratz is starting a $500 million fund to invest in cryptocurrencies, initial coin offerings and related companies. Although he says digital currencies like bitcoin show signs of forming a bubble, former hedge fund manager Michael Novogratz is going all-in. The former Fortress Investment Group manager says he's…