Svmuu News According to Gate data, Japanese and South Korean stock markets opened lower on Monday. The Nikkei 225 index opened on April 13 (Monday) down 557.91 points, a decrease of 0.98%, at 56,366.20 points. The South Korean KOSPI index opened on April 13 (Monday) down 127.08 points, a decrease of 2.17%, at 5,731.79 points.