Mikhail Prokhorov is a crazy Russian oligarch with billions of dollars and a professional basketball organization. He spent an absurd amount of money on a personal jet ski video (see above), lost his 200-foot yacht that makes him seasick, and doesn't use a computer. Now he's quitting business in order to focus on politics.
Most people in America know Prokhorov as the owner of the Brooklyn Nets (although, many probably believe Jay-Z to be the owner despite his owning about 1/15th of 1 percent of the team). But before he bought them he had already made billions in Russia.
His interest in politics is rather recent, but that didn't stop him from running against Vladamir Putin in this year's presidential election. He just announced that he will be joining his political party (that he founded), The Civil Platform Party, full-time and leaving his business interests to his partners.