Local securities firms in South Korea that allow daytime trading of US stocks for local investors are planning to temporarily suspend the service due to a recent order cancellation incident. The Korea Financial Investment Association announced that 19 brokerage houses affected by the cancellation of orders by the US overnight trading platform operator, Blue Ocean Technologies, will suspend the service from Friday. The association has called for an investigation into the system failure and preventive measures to be taken. Blue Ocean Technologies, which provides after-hours trading for local investors, shut down its matching engine on August 5, leading to the cancellation of orders worth 630 billion won across 90,000 accounts. The Financial Supervisory Service reported that all gains and losses from the canceled orders were nullified. Despite plans to resume full trading of US shares, the association has decided to delay this in order to ensure system stability and protect investors. Korean investors have faced challenges with Blue Ocean Technologies in the past, including unexpected trading shutdowns and transaction errors. As the sole overnight trading platform for US shares, all local brokerage houses offering daytime trading services rely on the platform.