Mt GOX

Mt. Gox (short for "Magic: The Gathering Online eXchange") began in 2007 as a trading site for a card game before its domain was repurposed in 2010 as a exchange for Bitcoin. Under CEO Mark Karpelès, who bought the platform in 2011, it grew into the dominant venue for buying and selling Bitcoin, at one point routing more than 70% of all global trading volume.

Behind the scenes, the exchange was far less solid than its market share suggested. Investigators later traced the breach to late 2011, when attackers gained access to Mt. Gox's online hot wallet and quietly siphoned coins for years while the company kept operating as if nothing were wrong. It never properly reconciled customer balances against its own holdings, so the shortfall went unnoticed until withdrawals started failing in early 2014.

On February 28, 2014, Mt. Gox filed for civil rehabilitation in Tokyo, disclosing that roughly 850,000 BTC belonging to the company and its customers, worth hundreds of millions of dollars at the time, was missing. The announcement sent Bitcoin's price tumbling and became crypto's defining early example of catastrophic exchange failure and self-custody risk.

Karpelès was later convicted only of data falsification, not theft. A separate figure tied to laundering the stolen funds was arrested in 2017. Creditor repayments, approved by court in 2021, began rolling out in cash and crypto from 2023 onward, though the trustee has repeatedly pushed the final distribution deadline, now set for October 2026, more than a decade after the collapse. Mt. Gox remains the reference point whenever a project or exchange gets spectacularly rekt.