A deepening slump in prices for oil, metals, and other commodities sent stock prices lower Thursday. The Dow and the Standard & Poor's 500 index are now negative for the year. The Dow sank 254 points, or 1.4%, to 17,448. The S&P 500 lost 29 points, or 1.4%, to 2,045 and the Nasdaq composite fell 61 points, or 1.2%, to 5,005.
The downturn extended a slide that began early this month and has eroded some of the gains from a powerful rally in October. Crude oil fell below $42 a barrel, its lowest price since August, while copper, gold and silver reached six-year lows. Energy, mining, and metals companies fell. Caterpillar, Exxon Mobil and Chevron had the biggest losses in the Dow Jones industrial average.