The Korea Exchange (KRX) said Wednesday it will close a night trading session of derivatives on Sept. 23, a day before the Chuseok holiday begins. The planned closure, which will begin at 6 p.m. on Sept. 23 and end at 6 a.m. on Sept. 24, is aimed at supporting market participants' risk management during the holiday that runs from Sept. 24-27, the KRX said in a statement. The measure will apply to all KRX derivative products traded at night, it said. The derivative products include futures for the KOSPI 200, the U.S. dollar and three-year government bonds, according to the statement.