From wikipedia:
Customer complaints about long delays were mounting as of February 2014, with more than 3,300 posts in a thread about the topic on the Bitcoin Talk online forum.
On 7 February 2014, Mt. Gox halted all bitcoin withdrawals. The company said it was pausing withdrawal requests “to obtain a clear technical view of the currency processes”. The company issued a press release on February 10, 2014, stating that the issue was due to transaction malleability: “A bug in the bitcoin software makes it possible for someone to use the bitcoin network to alter transaction details to make it seem like a sending of bitcoins to a bitcoin wallet did not occur when in fact it did occur. Since the transaction appears as if it has not proceeded correctly, the bitcoins may be resent. Mt Gox is working with the bitcoin core development team and others to mitigate this issue.”
On 17 February 2014, with all Mt. Gox withdrawals still halted and competing exchanges back in full operation, the company published another press release indicating the steps it claimed it was taking to address security issues. In an email interview with the Wall Street Journal, CEO Mark Karpelès refused to comment on increasing concerns among customers about the financial status of the exchange, did not give a definite date on which withdrawals would be resumed, and wrote that the exchange would impose "new daily and monthly limits" on withdrawals if and when they were resumed. A poll of 3,000 Mt. Gox customers by CoinDesk indicated that 68% of polled customers were still awaiting funds from Mt. Gox. The median waiting time was between one and three months, and 21% of poll respondents had been waiting for three months or more.
On 20 February 2014, with all withdrawals still halted, Mt. Gox issued yet another statement, not giving any date for the resumption of withdrawals. A protest by two bitcoin enthusiasts outside the building that houses the Mt. Gox headquarters in Tokyo continued. Citing "security concerns", Mt. Gox moved its offices to a different location in Shibuya. Bitcoin prices quoted by Mt. Gox dropped to below 20% of the prices on other exchanges, reflecting the market's estimate of the unlikelihood of Mt. Gox paying its customers.
On 23 February 2014, Mt. Gox CEO Mark Karpelès resigned from the board of the Bitcoin Foundation. The same day, all posts on its Twitter account were removed.
On 24 February 2014, Mt. Gox suspended all trading, and hours later its website went offline, returning a blank page. A leaked alleged internal crisis management document claimed that the company was insolvent, after having lost 744,408 bitcoins in a theft which went undetected for years.
Six other major bitcoin exchanges released a joint statement distancing themselves from Mt. Gox, shortly before Mt. Gox's website went offline.
On 25 February 2014, Mt. Gox reported on its website that a "decision was taken to close all transactions for the time being", citing "recent news reports and the potential repercussions on Mt Gox's operations". Chief executive Mark Karpelès told Reuters that Mt. Gox was "at a turning point".
From 1 February 2014 until the end of March, during the period of Mt. Gox problems, the value of bitcoin declined by 36%.
On 28 February 2014 Mt. Gox filed in Tokyo for a form of bankruptcy protection from creditors called minji saisei (or civil rehabilitation) to allow courts to seek a buyer, reporting that it had liabilities of about 6.5 billion yen ($65 million, at the time), and 3.84 billion yen in assets.
The company said it had lost almost 750,000 of its customers' bitcoins, and around 100,000 of its own bitcoins, totaling around 7% of all bitcoins, and worth around $473 million near the time of the filing. Mt. Gox released a statement saying, "The company believes there is a high possibility that the bitcoins were stolen,” blamed hackers, and began a search for the missing bitcoin. Chief Executive Karpelès said technical issues opened up the way for fraudulent withdrawals.
Mt. Gox also faces lawsuits from its customers.
On 9 March 2014, Mt. Gox filed for bankruptcy protection in the US, to halt U.S. legal action temporarily by traders who alleged the bitcoin exchange operation was a fraud.
On 20 March 2014, Mt. Gox reported on its website that it found some bitcoins — worth around $116 million — in an old digital wallet used prior to June 2011. That brought the total number of bitcoins the firm lost down to 650,000, from 850,000.
New evidence presented in April 2015 by Tokyo security company WizSec led them to conclude that "most or all of the missing bitcoins were stolen straight out of the Mt. Gox hot wallet over time, beginning in late 2011."
On April 14, Mt. Gox lawyers said that Karpelès would not appear for a deposition in a Dallas court, or heed a subpoena by FinCEN. On 16 April 2014, Mt. Gox gave up its plan to rebuild under bankruptcy protection, and asked a Tokyo court to allow it to be liquidated.
In a 6 Jan 2015 interview, Kraken bitcoin exchange CEO Jesse Powell discussed being appointed by the bankruptcy trustee to assist in processing claims by the 127,000 creditors of Mt. Gox.
CEO Karpelès was arrested in August 2015 by Japanese police and charged with fraud and embezzlement, and manipulating the Mt. Gox computer system to increase the balance in an account -- this charge was not related to the missing 650,000 bitcoins. After he was interrogated, Japanese prosecutors accused him of misappropriating Y315m ($2.6m) in bitcoin deposited into their trading accounts by investors at Mt. Gox, and moving it into an account he controlled, approximately six months before Mt. Gox failed in early 2014.
By May 2016, creditors of Mt. Gox had claimed they lost $2.4 trillion when Mt. Gox went bankrupt, which they asked be paid to them. The Japanese trustee overseeing the bankruptcy said that only $91 million in assets had been tracked down to distribute to claimants, despite Mt. Gox having asserted in the weeks before it went bankrupt that it had more than $500 million in assets. The trustee's interim legal and accounting costs through that date, to be paid ultimately by creditors, were $5.5 million.
- Mark Karpelès's entry in this repository
- Mt. Gox on Wikipedia
- 25-Feb-2014 Antonopoulos.com - Statement on Mt.Gox by Andreas Antonopoulos