$72M worth of bitcoins stolen from Bitfinex exchange in Hong Kong

Nearly 120,000 units of digital currency bitcoin worth about US$72 million was stolen from the exchange platform Bitfinex in Hong Kong, rattling the global bitcoin community in the second-biggest security breach ever of such an exchange. Bitfinex is the world's largest dollar-based exchange for bitcoin, and is known in the digital currency community for having deep liquidity in the U.S. dollar/bitcoin currency pair. Zane Tackett, Director of Community & Product Development for Bitfinex, told Reuters yesterday that 119,756 bitcoin had been stolen from users' accounts and that the exchange had not yet decided how to address customer losses.

"The bitcoin was stolen from users' segregated wallets," he said. The company said it had reported the theft to law enforcement and was cooperating with top blockchain analytic companies to track the stolen coins. Last year, Bitfinex announced a tie-up with Palo Alto-based BitGo, which uses multiple-signature security to store user deposits online, allowing for faster withdrawals.

"Our investigation has found no evidence of a breach to any BitGo servers," BitGo said in a Tweet.

"With users' funds secured using multi-signature technology in partnership with BitGo, a lot more is at stake for the backbone of the bitcoin industry, with its stalwarts and prided tech under fire," said Charles Hayter, chief executive and founder of digital currency website CryptoCompare. The security breach comes two months after Bitfinex was ordered to pay a $75,000 fine by the U.S. Commodity and Futures Trading Commission in part for offering illegal off-exchange financed commodity transactions in bitcoin and other digital currencies.

Tuesday's breach triggered a slump in bitcoin prices and was reminiscent of events that led to the 2014 collapse of Tokyo-based exchange Mt Gox, which said it had lost about $500 million worth of customers' Bitcoins in a hacking attack.