Alphabiz - Trading Glitch Disrupts U.S. Stock Orders at Multiple Korean Brokerages

Photo courtesy of Yonhap News

[Alpha Biz= Kim Jisun] Seoul, October 9 — Several South Korean securities firms experienced trading disruptions in U.S. stock transactions overnight due to a system failure at a U.S. intermediary broker, according to industry sources.


The incident affected at least five brokerages — Toss Securities, Daishin Securities, Meritz Securities, NH Investment & Securities, and KakaoPay Securities — causing order delays and execution failures on their mobile trading systems (MTS).


Toss Securities said that between 10:30 p.m. and 10:47 p.m. (KST) on October 8, some U.S. stock orders failed to process normally. The company noted that order corrections and cancellations for unexecuted trades were also affected, though trading returned to normal after 10:47 p.m.


Toss confirmed that the disruption originated from a system error at its U.S. intermediary broker, not from its own domestic servers.


Daishin Securities issued a similar notice around 10:55 p.m., citing “network issues with overseas order lines.” A follow-up update at 11:14 p.m. stated that the issue had been resolved after the U.S. intermediary restored its systems.


The incident highlights ongoing challenges faced by Korean retail brokers as U.S. stock trading via mobile apps surges in popularity among local investors.

Alphabiz Reporter Kim Jisun(stockmk2020@alphabiz.co.kr)