NEW YORK — A deepening slump in prices for oil, metals and other commodities sent stock prices lower Thursday.

Major market indexes opened lower and the selling accelerated as the day wore on. The drop in oil and metals prices hurt mining, metals and energy stocks. Stocks began sliding early this month and have returned some of the gains from a powerful rally in October.

The Dow Jones industrial average sank 254.15 points, or 1.4 percent, to 17,448.07. The Standard & Poor’s 500 lost 29.03 points, or 1.4 percent, to 2,045.97. The Nasdaq composite index fell 61.94 points, or 1.2 percent, to 5,005.08.

The S&P 500 has fallen for six out of the last seven days, and Thursday’s decline was the largest over that span. While October was the best month for the market in four years, the S&P 500 is now down slightly this year. The Dow average is also lower in 2015.

Mike McGlone, head of U.S. research for ETF Securities, said investors are coming to grips with the fact that the Federal Reserve is about to start raising interest rates, ending an era of stimulus policies that have boosted stocks. At the same time, stocks could get hurt by warning signs about the U.S. economy, such as weak jobs data or disappointing earnings.

Precious metals prices surged during the Great Recession, but in recent years many investors bought stocks instead, leading to a sustained slide in the prices of gold and silver.

Metals such as copper and steel have been hurt by the sluggish global economy, and copper prices are down 23 percent this year. All three fell Thursday after the head of Europe’s central bank said new stimulus measures may be put in place next month.