On February 24, 2014, Mt Gox abruptly halted all Bitcoin transactions and took its website offline hours later. The exchange, which had been handling over 70% of global BTC trades, had been bleeding funds for years. Hackers stole the private keys to a wallet in September 2011 and slowly drained both user deposits and the platform's own reserves. In total, 850,000 BTC — worth roughly $450 million at the time and accounting for about 7% of all Bitcoin in existence — disappeared.
From card trading to crypto dominance
Mt Gox started in 2007 as Magic: The Gathering Online Exchange, a platform for trading digital cards from the fantasy game. Founder Jed McCaleb pivoted to Bitcoin in 2010 and sold the site to French developer Mark Karpeles a year later. By 2013, Mt Gox processed more than 70% of all Bitcoin transactions worldwide, with tens of thousands of active users.
Bankruptcy and investigation
On February 28, 2014, Mt Gox filed for bankruptcy protection in the U.S., revealing that hackers had stolen 100,000 BTC from its own reserves in addition to the user funds. Investigators traced the root cause to a private key theft in September 2011. In May 2016, Kraken — which assisted in the probe — completed collecting claims from about 24,750 creditors. Tokyo-based security firm WizSec suggested the thefts began as early as 2011, when the exchange lost around $400,000 worth of Bitcoin.
Payouts drag on for a decade
A Japanese court approved a rehabilitation plan in September 2018, setting aside roughly $1 billion for creditors. The first payments went out in December 2023 — nearly ten years after accounts were frozen. On March 25, 2025, Arkham Intelligence flagged major wallet movements: 893 BTC to a new address, 10,608 BTC to another Mt Gox-controlled wallet, and a test transfer of 0.000017 BTC to Kraken. These came after transfers of 12,000 BTC on March 6 and 11,833 BTC on March 11, some of which ended up on Bitstamp. As of March 2025, Mt Gox still holds about 35,000 BTC (worth ~$3.08 billion). Last year, the repayment deadline was pushed from October 31, 2024, to October 31, 2025, due to verification delays.
Who was behind the hack?
The identity of the attacker remains unknown. Theories range from an inside job by someone with system access to involvement of North Korean hackers aiming to destabilize financial markets, but no evidence has surfaced to confirm any of them.
Legacy
Had Mt Gox survived, it would likely be the dominant exchange today, moving billions daily. Instead, its collapse forced the crypto industry to rethink security and opened the door for regulatory frameworks focused on consumer protection. The 850,000 BTC loss led to years of lawsuits, and the estate continues to process claims to this day.