Mt. Gox was a bitcoin exchange based in Shibuya, Tokyo, Japan. Launched in 2010, it was handling over 70% of all bitcoin (BTC) transactions worldwide by early 2014 when it abruptly ceased operations amid revelations of its involvement in the loss/theft of hundreds of thousands of bitcoins, 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." 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 that went undetected for years.

By May 2016, creditors of Mt. Gox had claimed they lost $2.4 trillion when Mt. Gox went bankrupt, which they asked to 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. On 15 January 2021, Bloomberg News reported CoinLab Inc. had made an agreement with Nobuaki Kobayashi, the trustee to the Mt. Gox bankruptcy, and the Mt. Gox Investment Fund LP, a unit of Fortress Investment Group. As much as 90% of the remaining Bitcoin tied up in bankruptcy proceedings would be offered to creditors.

At the creditors' meeting on 20 October 2021, it was announced that the Civil Rehabilitation Plan was accepted by 99% of the creditors (representing 83% of the total amount of voting rights) and that billions of dollars in Bitcoin would be provided as compensation. The plan was officially approved on 16 November 2021. On April 6, 2023, MtGox announced that the deadline for filing claims for damages had expired. Payments are promised to begin before October 31, 2023.