A man shelters under an umbrella as he walks past the London Stock Exchange in London, Britain. World stock markets plunged on Monday, as a near 9-percent dive in China shares and a sharp drop in the dollar and major commodities sent investors rushing for the exit. The Dow Jones Industrial Average dropped more than 1,000 points as Wall Street opened, and the benchmark Standard & Poor's 500 index slid more than 2.5 percent, a drop that puts it nearly 10 percent below its record high.