Mt. Gox is abandoning its plan for a financial comeback after it lost track of nearly half a billion dollars in Bitcoin. The Tokyo-based giant virtual-currency exchange is asking to be liquidated after it collapsed in February with liabilities of $63.3 million. The company filed for bankruptcy protection earlier in the year, but it appears unable to make a comeback. Of the 850,000 Bitcoins lost on Mt. Gox’s watch, only 200,000 have been recovered. According to today’s virtual market value, that means $325 million is still missing.