South Korea opens probe into Bithumb after $40–44B Bitcoin fat-finger error

South Korea’s Financial Supervisory Service (FSS) has launched a formal investigation into major exchange Bithumb after a February 6 operational ‘fat-finger’ error. During a promotional “Random Box” payout an employee entered rewards in BTC units instead of Korean won, momentarily crediting roughly 620,000 BTC (about $40–$44 billion) to user accounts — far exceeding Bithumb’s disclosed reserves of about 42,000–46,000 BTC. Bithumb froze affected accounts and halted trading and withdrawals within roughly 35 minutes and recovered most of the miscredited coins, but some BTC — reportedly worth millions — were traded or withdrawn before controls took effect. Regulators upgraded an earlier inspection into a high-intensity probe after on-site findings raised red flags about internal controls, ledger-management systems and reserves accuracy. The FSS is examining potential breaches of the Virtual Asset User Protection Act, single-operator transfer authorizations, liquidity and withdrawal risks, and the exchange’s custody practices. FSS Governor Lee Chan-jin warned the incident exposed systemic weaknesses; potential outcomes include fines, sanctions, corrective mandates or temporary suspension. Under Korean law, users who sold mistakenly credited BTC may be required to return proceeds as unjust enrichment. Traders should monitor regulatory announcements, account freezes or forced reversals, potential withdrawal or liquidity restrictions on Bithumb, and short-term volatility in BTC and Korea-listed crypto assets as market sentiment and trust in exchange reserves may shift.