Mt. Gox, once the dominant exchange for bitcoin trading, on Friday said more than $470 million of the virtual currency vanished from its digital coffers, kicking into high gear a search for the missing money by victims and cybersleuths.
Mt. Gox Chief Executive Mark Karpelès said technical issues had opened the way for fraudulent withdrawals, though he didn't provide details.Acting alone and in groups, the people stepped up their efforts after Mt. Gox filed for bankruptcy protection in Japan and confirmed rumors it had lost almost 750,000 of its customers' bitcoins, as well as roughly 100,000 of its own.
"There was some weakness in the system, and the bitcoins have disappeared. I apologize for causing trouble," Mr. Karpelès said at a packed news conference at a Tokyo courthouse after the bankruptcy filing.
The disappearance underscores the risks of currencies that exist only online and aren't backed by a central bank. Mt. Gox wasn't overseen by national regulators, so there is no entity to step in and back investors' deposits.
