Mt. Gox


Mt. Gox was a bitcoin exchange based in Shibuya, Tokyo, Japan. Launched in 2010, it was handling over 70% of all bitcoin transactions worldwide by early 2014, when it abruptly ceased operations amid revelations of its involvement in the loss/theft of hundreds of thousands of bitcoin, then worth hundreds of millions in US dollars.
In February 2014, Mt. Gox suspended trading, closed its website and exchange service, and filed for bankruptcy protection from creditors. In April 2014, the company began liquidation proceedings. Although 200,000 bitcoins have since been "found", the reasons for the disappearance—theft, fraud, mismanagement, or a combination of these—were initially unclear. 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 cryptocurrency wallet over time, beginning in late 2011."
The collapse of Mt. Gox and the subsequent arrest and conviction of former CEO Mark Karpeles led Japan to create the first formal regulations for cryptocurrency exchanges and virtual currencies.

Founding (2006–2010)

In late 2006, programmer Jed McCaleb thought of building a website for users of the Magic: The Gathering Online tradable card game service, to let them trade "Magic: The Gathering Online" cards like stocks. In January 2007, he purchased the domain name mtgox.com, short for "Magic: The Gathering Online eXchange". Initially in beta release, sometime around late 2007, the service went live for approximately three months before McCaleb moved on to other projects, having decided it was not worth his time. In 2009, he reused the domain name to advertise his card game The Far Wilds.
In July 2010, McCaleb read about bitcoin on Slashdot, and decided that the bitcoin community needed an exchange for trading bitcoin and regular currencies. On 18 July, Mt. Gox launched its exchange and price quoting service deploying it on the spare mtgox.com domain name.

Security breach, user DB leak, and invalid addresses (2011)

In March 2011, McCaleb sold the site to French developer Mark Karpelès, who was living in Japan, stating that "to really make mtgox what it has the potential to be would require more time than I have right now. So I've decided to pass the torch to someone better able to take the site to the next level."
On 13 June 2011, the Mt. Gox bitcoin exchange reported some BTC 25,000 had been stolen from 478 accounts. Then on Friday 17 June, Mt. Gox's user database leaked for sale to pastebin, signed by ~cRazIeStinGeR~ and tied to auto36299386@hushmail.com. The theft of Bitcoins from Mt. Gox accounts continued, reportedly, throughout that day. On 19 June, a stream of fraudulent trades caused the nominal price of a bitcoin to fraudulently drop to one cent on the Mt. Gox exchange, after a hacker allegedly used credentials from a Mt. Gox auditor's compromised computer to transfer a large number of bitcoins illegally to himself. He used the exchange's software to sell them all nominally, creating a massive "ask" order at any price. Within minutes the price corrected to its correct user-traded value. Accounts with the equivalent of more than $8,750,000 were affected. To prove that Mt. Gox still had control of the coins, the move of 424,242 bitcoins from "cold storage" to a Mt. Gox address was announced beforehand, and executed in Block 132749.
In October 2011, about two dozen transactions appeared in the block chain that sent a total of BTC 2,609 to invalid addresses. As no private key could ever be assigned to them, these bitcoins were effectively lost. While the standard client would check for such an error and reject the transactions, nodes on the network would not, exposing a weakness in the protocol.

Processor of most of world's bitcoin trades; issues (2013)

On 22 February 2013, following the introduction of new anti-money laundering requirements by e-commerce/online payment system company Dwolla, some Dwolla accounts became temporarily restricted. As a result, transactions from Mt. Gox to those accounts were cancelled by Dwolla. The funds never made it back to Mt. Gox accounts. The Mt. Gox help desk issued the following comment: "Please be advised that you are actually not allowed to cancel any withdrawals received from Mt. Gox as we have never had this case before and we are working with Dwolla to locate your returned funds." The funds were finally returned on 3 May, nearly three months later, with a note: "Please be advised never to cancel any Dwolla withdrawals from us again".
In March 2013, the bitcoin transaction log or "blockchain" temporarily forked into two independent logs, with differing rules on how transactions could be accepted. The Mt. Gox bitcoin exchange briefly halted bitcoin deposits. Bitcoin prices briefly dipped by 23%, to $37, as the event occurred, before recovering to their previous level in the following hours.
By April 2013 and into 2014 the site had grown to the point where it was handling over 70% of the world's bitcoin trades, as the largest bitcoin intermediary and the world's leading bitcoin exchange. With prices increasing rapidly, Mt. Gox suspended trading from 11 to 12 April for a "market cooldown". The value of a single bitcoin fell to a low of $55.59 after the resumption of trading, before stabilizing above $100. Around mid-May 2013, Mt. Gox traded 150,000 bitcoins per day, per Bitcoin Charts.
On 2 May 2013 CoinLab filed a $75 million lawsuit against Mt. Gox, alleging a breach of contract. The companies had formed a partnership in February 2013 under which CoinLab was to handle all of Mt. Gox's North American services. CoinLab's lawsuit contended that Mt. Gox failed to allow it to move existing U.S. and Canadian customers from Mt. Gox to CoinLab.
On 15 May 2013 the US Department of Homeland Security issued a warrant to seize money from Mt. Gox's U.S. subsidiary's account with payment processor Dwolla. The warrant suggested the US Immigration and Customs Enforcement, an investigative branch of the DHS, asserted that the subsidiary, which was not licensed by the US Financial Crimes Enforcement Network, was operating as an unregistered money transmitter in the US. Between May and August the DHS seized $2.9 million from the Dwolla account and another $2.1 million from the company's Wells Fargo account. On 29 June 2013, Mt. Gox received its money services business license from FinCEN.
Mt. Gox suspended withdrawals in US dollars on 20 June 2013. The Mizuho Bank branch in Tokyo that handled Mt. Gox transactions pressured Mt. Gox from then on to close its account. On 4 July 2013, Mt. Gox announced that it had "fully resumed" withdrawals, but as of 5 September 2013, few US dollar withdrawals had been successfully completed.
On 5 August 2013, Mt. Gox announced that it incurred "significant losses" due to crediting deposits which had not fully cleared, and that new deposits would no longer be credited until the funds transfer was fully completed.
Wired Magazine reported in November 2013 that customers were experiencing delays of weeks to months in withdrawing cash from their accounts. The article said that the company had "effectively been frozen out of the U.S. banking system because of its regulatory problems".

Withdrawals halted; trading suspended; bitcoin missing (2014)

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 10 February 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.
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 the company's 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%.
The United States Department of Justice identified Alexander Vinnik, owner of the BTC-e bitcoin exchange, as an alleged key figure in the laundering of Mt. Gox's stolen bitcoins.