Mt. Gox
The exchange that held most of Bitcoin's trading — then lost 850,000 coins.
In plain words
Mt. Gox, a Tokyo exchange, handled around 70% of all bitcoin trading at its peak. In February 2014 it froze withdrawals, went dark, and filed for bankruptcy: roughly 850,000 bitcoin — customers' coins, held in Mt. Gox's custody — were gone, siphoned by thieves over years while the books said otherwise. About 200,000 were later found. Creditors waited a decade for partial repayment. Every lost coin had one address: a company's, not its owners'.
Why it matters
- The disaster that taught "not your keys, not your coins."
- Custody risk is invisible until the day it is total.
- Bitcoin's rules held; a company's promises broke. Learn the difference.
Numbers that matter
- ~850,000 BTC — missing in 2014; about 200,000 recovered.
- ~70% — Mt. Gox's share of world bitcoin trading at its peak.
- 10 years — before creditor repayments began, in 2024.
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Updated 2026-07-30