On February 6, 2026, a fat-finger input turned a routine promotion into one of the largest accounting anomalies in crypto history. The Seoul court has now ruled in favor of Bithumb, confirming the obligation to return mistakenly credited BTC for users who sold them.
🔑 Key takeaways
- A unit error (« BTC » instead of « KRW ») credited 620,000 BTC to 249 winners, worth over $40 billion at the time.
- About 1,788 BTC were sold before accounts were frozen, triggering a 17% drop on the BTC/KRW pair.
- Bithumb recovered 99.7% of the funds, but 7 BTC remain unreturned.
- On August 27, 2026, the Seoul civil court ruled in Bithumb’s favor in the second-largest of four suits (194 million won).
- The FSC ordered an inspection of internal controls across all South Korean crypto exchanges.
A fat-finger input with historic consequences
On February 6, 2026, Bithumb mistakenly distributed roughly 620,000 BTC to 249 participants of a promotional campaign. The intended amount was approximately 620,000 South Korean won (KRW), or about $460 per winner. A staff member entered « BTC » instead of « KRW » in the unit field of the settlement form, so the system credited each account with 620,000 bitcoin. In total, more than $40 billion at the prevailing price was booked onto the platform’s internal ledgers.
Flash crash on BTC/KRW and platform response
Within minutes of the distribution, several users sold the bitcoin they had just been credited with. According to data reported by Bithumb and multiple media outlets, about 1,788 BTC were offloaded before the platform froze the affected accounts. This wave of selling pushed the bitcoin price on the BTC/KRW pair down to roughly 80 million won (around $54,000), a drop of about 17% from the prior level.
« If the ledger data and the actual assets had been reconciled in real time, this kind of ghost-coin situation could never have occurred. »
Hwang Souk-jin, Professor at Dongguk University’s Graduate School of Information Security
Bithumb said it reacted within minutes of detecting the error and reversed most of the entries. The company recovered 99.7% of the misallocated bitcoin, leaving about 125 BTC still missing at the time. After several months of recovery efforts, an outstanding balance of 12.3 billion won (about $8.3 million) remained unpaid; this amount was later reduced to seven bitcoin still unreturned.
Real reserves vs. ghost coins: the accounting gap exposed
The incident exposed a gap between the platform’s internal bookkeeping and its actual reserves. According to information disclosed by Bithumb, total bitcoin reserves on the exchange are estimated at around 43,000 BTC, of which only 175 belong to the company itself, the remainder corresponding to customer deposits. The way centralized exchanges operate—handling balances internally without any on-chain movement until a withdrawal occurs—allowed the error to propagate instantly across user accounts.
| Platform | 24h volume (USD) | Control mechanism |
|---|---|---|
| Upbit | $788 million | Proof of reserves, blocks excess distributions |
| Bithumb | $388 million | Internal ledger, post-trade controls |
| Coinone | — | Multi-layer approval |
| Korbit | — | Double-entry accounting |
Other market players highlighted their own security frameworks. Upbit, the country’s largest exchange, said it blocks any distribution that exceeds actual holdings and continuously reconciles internal balances against blockchain wallets through a proprietary proof-of-reserves system. Coinone stated that all asset movements, including promotional payouts, are subject to multi-layer verification and approval procedures. Korbit noted it uses double-entry accounting similar to that of traditional financial institutions.
Court ruling: Bithumb wins the case
On the legal front, Bithumb filed several unjust enrichment suits. In March, the company sued four users who had sold the mistakenly credited bitcoin and refused to return them. On August 27, 2026, the Seoul District Civil Court (90th division) issued its first ruling in favor of Bithumb in one of these cases, involving a user referred to as « A. » The claim amounted to about 194 million won (approximately $140,000). This is the second-largest of the four proceedings; the other three target sums of roughly 500 million won ($360,000), 14.8 million won ($11,000), and 5 million won ($3,600).
« This was an expected outcome, since the users had no legal basis to keep the virtual assets in question. »
Lee Jeong-yeop, attorney at law firm Logip
The case sets a notable precedent. In 2023, exchange Bybit already won a lawsuit after mistakenly distributing roughly $15.3 million in USDT and being denied restitution. Bithumb has also asked the court to provisionally seize seven bitcoin to secure recovery of the remaining funds. A follow-up civil proceeding is expected.
Toward tighter regulation of the sector
On the regulatory side, the Financial Services Commission (FSC) has ordered an inspection of internal control frameworks across all crypto exchanges in the country. The case is also expected to shape the next digital assets legislation, which could impose stronger requirements for internal controls, regular reserve audits, and stricter licensing standards.
« The most urgent task is to make internal control a core condition for granting licenses. »
Lee Jeong-soo, attorney and professor at Seoul National University School of Law
On the compensation side, Bithumb announced that customers who sold bitcoin at a depressed price will be refunded the full price difference plus 10%. All users logged in at the time of the incident will receive 20,000 won. The platform also transferred about 3 billion won to personal accounts and used around 10 billion won to purchase other assets.
Conclusion: a wake-up call for centralized exchanges
The Bithumb incident illustrates with unprecedented clarity how a human error, combined with the speed and irreversibility of crypto transactions, can turn a minor typo into a multi-billion-dollar financial crisis. The August 27, 2026 ruling makes clear that beneficiaries of an erroneous credit cannot keep the corresponding assets; it strengthens the legal position of exchanges in their recovery efforts. In the medium term, regulatory pressure from the FSC and the likely evolution of licensing standards could force the entire sector to adopt real-time reconciliation mechanisms between accounting ledgers and blockchain reserves, bringing centralized exchanges closer to the proof-of-reserves standards already in place at Upbit.
Sources
- The Block — Bithumb wins lawsuit
- Yahoo Finance — South Korean exchanges and $40B bitcoin
- Bloomberg — Fat-finger error
- Korea Herald — Bithumb incident
- CoinDesk — Bithumb asset seizure
This article is for informational and educational purposes only. It does not constitute investment advice. Do your own research (DYOR) before making any decision.
