Bithumb is under renewed scrutiny after some altcoin withdrawals on the South Korean exchange were delayed for more than 13 hours, prompting South Korea’s Financial Supervisory Service to examine the circumstances. Industry sources said a user who requested a withdrawal around 11 a.m. on Aug. 11 did not receive it until about 12:25 a.m. on Aug. 12. Customer service told users the delay was due to "insufficient balance," wording Bithumb later acknowledged was misleading and said it would revise, while maintaining that customer assets were being held and managed normally. The exchange said the delay occurred when withdrawal demand temporarily exceeded balances in hot wallets and assets had to be moved from cold wallets, a process it described as part of user asset protection. Users said the delay caused missed arbitrage opportunities as price gaps with other exchanges narrowed during the hold-up. Similar delays have reportedly happened before when newly listed altcoins on other venues triggered a surge in withdrawals, raising broader concerns about Bithumb’s reliability, asset management and communication. The FSS said moving assets from cold wallets to hot wallets can take time and that batch processing to reduce blockchain network costs such as gas fees may also contribute, but it plans a working-level review of the specific causes. The episode could also weigh on market perceptions as Bithumb prepares for a listing targeted for 2028, with customer asset management and stable withdrawals seen as central to exchange trust and internal controls.