TOKYO â" Mt. Gox, the troubled exchange for the virtual currency Bitcoin, filed for bankruptcy protection on Friday and said that it might have lost all of its customersâ coins in a hacking attack.
The Tokyo-based exchange, which warned earlier this month of a software flaw that may have allowed hackers to defraud it of Bitcoins, had halted all trading earlier this week.
Mark Karpeles, the companyâs chief executive, wearing a suit instead of his usual T-shirt, bowed in contrition and apologized in Japanese at a press conference in Tokyo.
âIâm truly sorry to have caused inconvenience,â he said.
The exchange has likely lost 800,000 Bitcoins, according to a person briefed on its holdings soon before the exchange went offline on Tuesday.
Mt. Gox had said on its website on Wednesday that it was still âworking very hardâ toward a resolution.
Investors in the exchange had said they did not expect to recover their money stashed on the Mt. Gox platform, which once accounted for four-fifths of the worldâs Bitcoin trading.
But Mt. Goxâs bankruptcy, filed under Japanâs Civil Rehabilitation Law, which is similar to Chapter 11 in the United States, will mean that a bankruptcy supervisor is set to develop a restructuring plan, and will also be responsible for handling any payment of claim distributions to its creditors. That process could take form several months to several years.
The exchange has liabilities of 6.5 billion yen, or $64 million, compared with total assets of 3.84 billion yen, the company said. It has 127,000 creditors.
The demise of Mt. Gox did not come as a surprise for many â" and has fanned skepticism in some quarters over the virtual currencyâs future in Japan.
âI didnât think something like this would last for long. I thought it would collapse at some point,â Taro Aso, the Japanese finance minister, told reporters earlier Friday, according to the Nikkei website.
He also suggested that Japan might move to regulate Bitcoin.
âNot everybody accepts it as a legitimate currency. And itâs unclear who should supervise it,â Mr. Aso said. âJapan must do something about it.â
Many Bitcoin advocates, however, have put Mt. Goxâs woes down to managerial and security incompetence and say that the technology underlying Bitcoins remains sound.
âItâs a simple case of gross mismanagement and neglect. But weâre seeing a lot of stronger Bitcoin companies now with better systems and proper staff,â said James MacWhyte, an early Bitcoin adopter and occasional Mt. Gox customer who is working to set up an association of Bitcoin users in Japan.
âCompetition is great. Mt. Gox had no competition for a long time, and thatâs how it got to where it got,â he said. âNow itâs time to raise the standard.â