What happened
The exchange that handled most of the world's bitcoin trading lost most of the bitcoin, slowly, over years, without noticing.
| When | February 2014 |
| What kind of failure | Exchange collapse |
| What it cost | About 850,000 BTC, roughly $450 million at the time |
The version the public saw
Mt. Gox was, at its peak, handling around seventy percent of all bitcoin transactions. It started life as a trading site for Magic: The Gathering cards, which is where the name comes from, and grew into the default place to buy bitcoin at a time when there were few alternatives.
Underneath the same period
Coins had been leaking out since 2011 through a compromised wallet key, and the company did not have the accounting to detect it. Deposits and withdrawals were reconciled badly or not at all. The exchange also ran on code that a single engineer maintained, with no version control for long stretches.
The sequence
Withdrawals slow down
Through late 2013 and early 2014 customers reported bitcoin withdrawals taking weeks. The company blamed a flaw in the bitcoin protocol itself, which was a real flaw and was not the reason.
Trading halts
On 7 February 2014 Mt. Gox suspended bitcoin withdrawals entirely. On 24 February the site went blank.
The number appears
A leaked internal document put the shortfall at 850,000 BTC, of which about 200,000 were later found in an old wallet format nobody had checked.
Bankruptcy, then twelve years
Mt. Gox filed in Japan in February 2014. Creditors have been waiting since. The repayment deadline has been extended repeatedly and now stands at October 2026.
The signals, before anybody knew the ending
None of these needed hindsight. Each one was public, or checkable, while the money was still there.
- Withdrawal delays explained by something outside the company's control
- No proof of reserves and no audit anybody could inspect
- A single point of failure in the engineering, publicly known at the time
- Support that stopped answering as the delays got longer
The aftermath
More than twelve years on, the estate is still distributing. The recovered coins are worth vastly more than the claims were when they were filed, which has made the process both unusually generous and unusually slow. The repayment deadline was pushed again in late 2025, to October 2026.
The part that changes what you do
Withdrawal delays are the single most reliable early signal that an exchange is in trouble, and they always come with a plausible technical explanation. The right response is to withdraw everything immediately and ask questions afterward. It costs a fee if you are wrong and it saves everything if you are right.
Common questions
Why is Mt. Gox still not resolved?
How were the coins actually stolen?
Did anyone go to prison?
Where to go next
Other cases like this one
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