On August 26 and 27, the Seoul Central District Court ruled in favor of Bithumb in two lawsuits against users who sold mistakenly credited bitcoins and did not return the funds. The South Korean publication Chosun Biz reported that the exchange is seeking to recover the money as unjust enrichment.

The first lawsuit involved a claim of 5 million won ($3,600), while the second was for 194 million won ($140,000). Additionally, two more cases worth 14.8 million won ($10,700) and 500 million won ($362,000) are still pending.

$40 Billion Error

These lawsuits stem from an incident that occurred in February 2026. During a promotional event, Bithumb intended to distribute a total of 620,000 won among 249 users, but an employee mistakenly used BTC instead of the Korean currency as the unit of payment. This error resulted in clients’ internal balances showing 620,000 BTC, valued at over $40 billion.

The exchange identified the mistake approximately 20 minutes later, freezing trading and withdrawals on the affected accounts. However, some recipients had already sold the credited coins, which caused a significant drop in Bitcoin's price on the platform.

According to financial authorities, before any transactions were completed, Bithumb managed to recover 618,214 BTC (99.7% of the erroneously credited amount). Clients sold an additional 1,786 BTC, and the trading platform later reported that about 93% of that volume was returned.

In March, the company filed four separate lawsuits against users who sold the assets and refused to return the proceeds.

Following the incident, the Financial Supervisory Service of South Korea (FSS) launched a comprehensive investigation, focusing on how the exchange could reflect a volume of Bitcoin on client accounts that far exceeded its actual reserves.

Stricter Regulations Emerge from the Error

In April, the FSC introduced new requirements for cryptocurrency exchanges as a result of the investigation initiated after the Bithumb incident.

The regulator mandated that exchanges implement automated checks of client balances against actual reserves every five minutes. For manual operations, including promotional payouts, automated verification, account segregation, and multi-level confirmation are now required.

The investigation into Bithumb itself has also progressed to the next stage. The FSS sent the exchange a report following the investigation and initiated procedures for potential sanctions. After receiving the exchange's explanations, the regulator will prepare a draft of measures to be submitted to the sanctions committee for review.

It is worth noting that in early August, Bithumb presented a roadmap for preparing for an IPO, aiming to complete the offering by 2028.