Falling stocks outpaced gaining ones three to two on the New York Stock Exchange. Consolidated trading volume was very light at 3.3 billion, versus 3.8 billion on Friday.
Bond prices fell. The yield on the 10-year Treasury note, which moves opposite to its price, fell to 2.60 percent from 2.62 percent late Friday. That yield helps set interest rates on mortgages and consumer loans.
"People are focused on the head winds more than the tail winds," said Walter Gerasimowicz, chief investment officer at Meditron Asset Management. He said investors are overlooking historically low interest rates and signs of corporate strength, choosing instead to focus on disappointing economic data.
Reports are due this week on the housing market, durable goods orders, consumer sentiment and a revision to second-quarter gross domestic product.Housing remains especially weak following the expiration of the government's tax credit earlier this year. Reports on existing and new home sales are due out Tuesday and Wednesday. Traders will be looking at Wednesday's report on durable goods orders to see if a slowdown in manufacturing was only temporary. Manufacturing has been one of the few bright spots in the broader economy this year. Hewlett-Packard shares fell 81 cents to $39.04, while 3Par jumped $8.05, or 44.6 percent, to $26.09. Dell fell 13 cents to $11.94.