Bitfinex

Bitfinex is a crypto-currency exchange trading and currency-storage platform based out of Hong Kong and owned and operated by iFinex Inc. Since 2014, it has been the largest Bitcoin exchange platform, with over 10% of the exchanges' trading. In 2016, Bitfinex was hacked, and $72 million in bitcoin was stolen from its customers.

In 2016, Bitfinex was the subject of the Bitfinex hack. In it, $72 million in bitcoin was stolen from the company's customer's accounts. Immediately thereafter, bitcoin's trading price plunged by 20%. After learning of the breach, Bitfinex halted all bitcoin withdrawals and trading.

In that hack, the second-biggest breach of a Bitcoin exchange platform, 119,756 units of bitcoin, which was about $72 million at the time, were stolen. Bitfinex first announced the security breach on August 2, 2016. The bitcoin was taken from users' segregated wallets and Bitfinex said it was tracking down the hack. Significant hacker funds transactions were signed off by Bitfinex's security provider, without full security.

Shortly after the hack, Bitfinex created BFX tokens, which were used to represent customers' stolen equity. The BFX tokens represented $1 and were issued to account for the value of customers cryptocurrencies at the time of the hack. In April of 2017, Bitfinex announced they had bought back all of the BFX tokens, essentially paying back all of customers lost funds. Some customers found this repayment to be inadequate, as the price of Bitcoin had nearly doubled in the time it took Bitfinex to repay customers. Despite many customer complaints, Bitfinex has continued to grow in market share of cryptocurrency trading.

In April 2017, Bitfinex announced that it was no longer able to let users withdraw their funds in USD, after Wells Fargo placed limitations on its wire transfers. Bitfinex sued Wells Fargo for the decision but dismissed the case few days later. As a consequence, Bitcoins were traded at a price around 100 USD higher than other exchanges as users started buying bitcoins in order to move them to other exchanges and withdraw their funds there.

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Wikipedia