Japan's Nikkei 225 stock index has plunged more than 12% as investors worried that the U.S. economy may be in worse shape than had been expected and dumped a wide range of shares. Tokyo's benchmark fell more than 4,400 points to 31,458.42 on Monday. It dropped 5.8% on Friday, logging its worst two-day decline ever. Its biggest single-day rout was a plunge of 3,836 points, or 14.9%, on the day dubbed “Black Monday” in October 1987. Share prices have fallen in Tokyo since the Bank of Japan raised its benchmark interest rate on Wednesday. The Nikkei index is now 3.8% below the level it was at a year ago.
