The Korea Exchange (KRX) issued a circuit breaker on the country's main stock market Monday amid extreme jitters following recent geopolitics surrounding U.S.-Israeli airstrikes on Iran and rising oil prices. The KRX issued the measure at 10:31 a.m., after the benchmark Korea Composite Stock Price Index (KOSPI) crashed 452.8 points, or 8.11 percent, to 5,132.07. Earlier in the day, the main bourse operator activated a sell-side sidecar, suspending sales for five minutes, which is triggered when the KOSPI 200 Futures index moves 5 percent or more for at least one minute. Investors kept watchful eyes on the global energy price volatility, with the U.S. benchmark West Texas Intermediate (WTI) crude surpassing $100 per barrel Sunday (U.S. time). The Korean won was trading at 1,497.4 won against the U.S. dollar as of 10:40 a.m., down 21 won from the previous session.