Japan's Nikkei stock index sank more than 4% on Monday, as the yen strengthened after Shigeru Ishiba won the ruling Liberal Democratic Party's leadership elections late last week. The 225-issue Nikkei Stock Average fell 1,849.22 points, or 4.64%, from Friday to 37,980.34. The broader Topix index fell 90.32 points, or 3.30 percent, to 2,650.62. Source: Qatar News Agency