Rain Leaves Grains Sagging

Prices for grains were slipping Monday as traders worried that excess rain would boost crop yields and lead to an oversupply in the market.

Corn contracts were lower by 1.5% at $3.76 a bushel, while those for wheat were off 0.6% at $6.02 a bushel.

"Corn's fall has some oomph behind it," says Tobin Gorey, a commodities strategist at Commonwealth Bank of Australia, in a daily research brief.

He adds that not only is the technical picture looking increasingly bad for corn prices, but also it seems to be dragging on the wheat futures also.

In the meantime, traders will be watching the weather in the Midwest, where the level of rainfall later this week is considered critical to helping determine crop yields this season.

Turning to the agriculture complex, shares of Corn Products International(CPO Quote) were down 1.4%, while Archer Daniels Midland(ADM Quote) was rising 0.3%.

Elsewhere, precious metals prices were softening, as well. Benchmark gold contracts were slipping $4 at $653 an ounce, and silver was off 16 cents at $12.86 an ounce.

The exchange-traded funds that track prices of the metals, the streetTracks Gold Shares(GLD Quote) and the iShares Silver Trust(SLV Quote), were retreating 0.5% and 1.3%, respectively.

As for base metals, copper prices were down 5 cents at $3.33 a pound. The price was down more than that earlier in the session, but perked up after some new housing data was released midmorning.

The PowerShares DB Base Metals(DBB Quote), which tracks the prices of copper and industrial metals, was down 0.9%.