Stocks gave up early gains Monday as a rising dollar stalled a rally in commodities.
Oil and other commodities had risen in early trading, pushing up shares of energy and materials companies, but by midmorning those gains were gone as the dollar turned higher against other currencies.
Changes in the dollar frequently push commodity prices up or down, since a higher dollar makes oil and other basic materials, which are priced in dollars, more expensive to non-U.S. investors.
The Dow Jones industrial average swung in a 200-point range, surrendering an early advance for a loss of about 100 points by late morning. Oil fell $1.16 to $79.34 per barrel on the New York Mercantile Exchange, having given up earlier gains.
Technology shares fared somewhat better than other parts of the market after Marvell Technology Group Ltd., which makes chips used in phone networks, raised its fiscal third-quarter revenue forecast. That helped the technology-focused Nasdaq composite index limit its losses.
RadioShack Corp.'s third-quarter sales topped expectations, giving a boost to retailers.
Richard Ross, global technical strategist at Auerbach Grayson in New York, said the direction of the dollar as well as volatility continues to drive trading.
"You're seeing this sort of waltz between the dollar and volatility and stocks," he said.
In midday trading, the Dow fell 120.62, or 1.2 percent, to 9,851.56. The index had been up 100 points in early trading.
The broader Standard & Poor's 500 index fell 13.29, or 1.2 percent, to 1,066.31, while the Nasdaq fell 17.11, or 0.8 percent, to 2,137.36.
More than two stocks fell for every one that rose on the New York Stock Exchange, where volume came to 548.9 million shares compared with 496.4 million shares traded at the same point Friday.
The Dow fell 0.2 percent last week, while the S&P 500 index fell 0.7 percent.
Bond prices slipped as the government prepared to auction more than $120 billion in debt this week. The yield on the benchmark 10-year Treasury note, which moves opposite its price, rose to 3.52 percent from 3.49 percent late Friday.
The dollar rose against most other major currencies, while gold fell.
Traders looked to another busy week of earnings reports. Investors will look for clues about a possible pickup in consumer spending when companies including Kellogg Co., Procter & Gamble Co. and Visa Inc. report earnings.
The energy and insurance industries also will be in focus throughout the week with ConocoPhillips and Exxon Mobil Corp. as well as Aetna Inc. and MetLife Inc. scheduled to release quarterly results.
Among companies reporting earnings, Marvell rose 33 cents, or 2.3 percent, to $14.91, while RadioShack rose $2.15, or 13.7 percent, to $17.81.
The Russell 2000 index of smaller companies fell 5.12, or 0.9 percent, to 595.74.
