The South Korean stock market suffered a severe sell-off, with the KOSPI index tumbling more than 8%, prompting the Korea Exchange to activate a circuit breaker and temporarily halt trading for 20 minutes. Earlier in the same day, a sell-side sidecar was triggered, suspending program trading for five minutes after KOSPI 200 futures fell by 5% or more and remained at that level for at least one minute. Asian markets opened broadly lower, with the KOSPI index starting the session down 5.93% and the KOSDAQ index down 3.63%, while Japan's Nikkei 225 fell 0.65% and Australia's S&P/ASX 200 slipped 0.38%.