An anonymous reader writes "Mt. Gox CEO Mark Karpeles wrote in a sworn declaration in the company's U.S. bankruptcy filing he suspected hundreds of thousands of bitcoins were missing on Feb. 7, more than two weeks before it finally halted trading. That means Mt. Gox allowed its customers to continue trading, knowing that its bitcoin stash was wiped out and collecting as much as US$900,000 in trading fees. Since Mt. Gox said it was also missing $27.3 million in cash from customer deposits, it raises the possibility that customers — despite seeing a cash balance displayed in their account — might have actually been buying bitcoins that did not exist, with cash that was already long gone."