APPETITE FOR WHEAT: Wheat has been climbing this week as investors worry that dry weather in Russia and the U.S. will crimp supply. Wheat climbed 3 percent, or 19 cents per bushel, to $6.5775.

COPPER GOES ITS OWN WAY: While precious metals like gold and silver rose, as investors sought refuge from the plummeting stock market, copper fell. The industrial metal lost about half a cent, to $3.4795 per pound.

OIL KEEPS FALLING: Oil prices fell in New York and London, as did heating oil and natural gas. Investors are still worrying that a possible slowdown in China and the U.S. will crimp demand.