The KOSPI index fell more than 8% in one minute on the 23rd afternoon, prompting the Korea Exchange (KRX) to trigger a circuit breaker.
The exchange said it triggered a level-1 circuit breaker at 2:33 p.m. that day on the main board. At that time, the KOSPI stood at 8,378.25 points, down 736.30 points (8.07%) from the previous closing level of 9,114.44.
A circuit breaker is triggered when the index falls 8% or more from the previous trading day and the drop lasts for one minute. When a level-1 circuit breaker is triggered, all stock trading is halted for 20 minutes.
This is the fourth circuit breaker this year. So far, the circuit breaker has been triggered only 10 times in total.
The exchange said the trigger was due to weakness in U.S. tech stocks, among other factors.