South Korea's KOSPI index dropped 4% shortly after market open on Tuesday, activating a sell-side circuit breaker for the first time in approximately two months. Program sell orders were suspended for five minutes due to volatility in KOSPI 200 index futures. At the time of the trigger, KOSPI 200 futures stood at 955.02 points, down 51.20 points or 5.08% from the previous close. The mechanism activates when futures fall more than 5% and sustain that level for one minute. This marks the first circuit breaker event since August 20 and the first sell-side activation since August 19.