The main bourse operator, the Korea Exchange (KRX), on Tuesday issued a sell-side circuit breaker, temporarily halting trading after a sharp drop sparked by market concerns over U.S. airstrikes on Iran. Selling of the KOSPI 200 Futures index was suspended for five minutes at 12:05 p.m., according to KRX. The index fell 47.75 points, or 5.09 percent, to 890.05 at that time. It marked the first sell-side circuit breaker since Jan. 6. A sell-side sidecar is triggered when the KOSPI 200 Futures index drops 5 percent or more for at least one minute.