MAY'S WILD RIDE: Wheat rose 2.6 percent as questions persisted about how much dry weather has affected the crop in Kansas. In a matter of two weeks, the price has hit a high for the year and also nearly hit a 2012 low, largely because of weather issues.

EUROPEAN WORRIES: Investors adjusted their portfolios ahead of the Memorial Day weekend in case there are developments in Europe's debt crisis or other parts of the world that could affect commodities when markets are closed.

DAY OF GAINS: Prices for gold, silver, industrial metals, oil, corn and soybeans rose. Natural gas fell.