Back in its 2013 heyday, when bitcoin soared from below $100 to over $1000 in the span of a few months (in no small part thanks to the collapse of the Cyprus banking system) there was only one real Bitcoin exchange: Magic: The Gathering Online Exchange, or Mt. Gox as it was better known, which had become the world’s largest hub for trading the digital currency. And then, as mysteriously as it had appeared, Mt. Gox went dark, and filed for bankruptcy after nearly half a billion dollars worth of bitcoin “disappeared.”