Mirae Asset Securities and Samsung Securities suffered smart order routing failures on March 14 as the Korea Exchange launched its real-time after-market session for the first time. Mirae users reported delayed confirmations, failed cancellations and new orders, executions at pre-cancellation prices, incorrect available balances and stale orders being filled. Mirae began routing SOR orders to KRX at 8:50 a.m., restoring normal processing before the 9:00 a.m. regular session, although some functions remained under remediation. Samsung experienced a roughly 10-minute SOR failure around 9:30 a.m. and switched order processing to KRX. The disruptions occurred as brokerages revised SOR systems, order-validity rules and handling procedures for the expanded KRX and NXT trading schedule. The scale of investor losses and whether compensation will be paid remain unresolved.