In this Sept. 28, 2016, photo, a man sets up a new bitcoin mining machine to connect to the internet at a bitcoin mine built beside a hydropower station in a remote valley in Aba prefecture in southwestern China's Sichuan province. The launch of a U.S. futures contract for bitcoin on Sunday, Dec 10, 2017, underscores the virtual currency's increasing mainstream acceptance, including in many parts of Asia, where it already has a wide following among speculators and investors. (Chinatopix via AP)