South Korean crypto exchange Bithumb mistakenly airdropped 620,000 BTC during a marketing event on February 6 due to a backend configuration error. The platform intended to distribute 620,000 won in cash rewards but accidentally set the unit to BTC, resulting in each of the 249 users receiving 2,000 BTC. This error caused the BTC/KRW trading pair to plummet by nearly 17% on Bithumb, while the global BTC market briefly fell by 3%, leading to $400 million in derivatives liquidations. Bithumb quickly restricted transactions and withdrawals, recovering over 99% of the erroneous payments within 35 minutes. The remaining 1,788 BTC sold were covered by the company's assets. The incident has prompted South Korea's Financial Supervisory Service to call for stronger regulatory measures, highlighting systemic vulnerabilities in centralized exchanges' internal ledgers.