Stocks are moving lower, led by declines in energy and mining companies as prices for oil and other commodities fall.

Chevron fell 1.7 percent in midday trading Monday, the most in the Dow Jones industrial average.

Mining company Freeport-McMoRan sank 8 percent after announcing that its co-founder was leaving.

The Dow average was down 83 points, or 0.5 percent, to 17,469 as of 12:38 p.m. ET Monday.

The Standard & Poor's 500 index lost 12 points, or 0.6 percent, to 2,049. The Nasdaq composite declined 33 points, or 0.7 percent, to 5,016.

The price of crude oil fell 3 percent to just under $37 a barrel in New York.

Bond prices rose. The yield on the 10-year Treasury note fell to 2.22 percent.