Japanese police on Saturday
arrested Mark Karpelès, the head of collapsed bitcoin exchange Mt. Gox, alleging that he manipulated the company’s computer system to increase the balance in an account. Tokyo-based Mt. Gox was once the world’s largest exchange platform for the virtual currency by trading volume, before it filed for bankruptcy in February 2014. Here are five things to know about Mt. Gox and Mr. Karpelès.