Richard Drew, Associated Press
Trader Joseph Lawler works on the floor of the New York Stock Exchange, Monday, Aug. 3, 2015.

NEW YORK — U.S. stocks fell on Monday, led by a slumping energy sector as the price of oil continued to fall. Investors were also watching the latest earnings releases. Tyson Foods dropped after cutting its earnings outlook for the year.

Keeping score: The Standard & Poor's 500 index fell 13 points, or 0.7 percent, at 2,088 as of 2:58 p.m. Eastern. The Dow Jones industrial average dropped 178 points, or 1 percent, to 17,510. The Nasdaq composite fell 33 points, or 0.7 percent, 5,095.

Energy: Benchmark U.S. crude shed $1.95 to $45.17 a barrel on the New York Mercantile Exchange, its lowest price in more than four months. The price of oil slumped 21 percent in July on evidence of a global supply glut and speculation that global demand is set to weaken.

The quote: The big drop in oil has pushed down gas prices, putting more money in consumer's pockets. That hasn't led to a pickup in spending yet, suggesting that consumers are saving the extra cash rather than spending it. That has surprised investors.

"There was this expectation that (the fall in oil prices) would translate into other areas, such as stronger consumer spending, and stronger (company) earnings," said Jennifer Ellison, a principal at San Francisco-based investment firm Bingham, Osborn & Scarborough. "But we're really not seeing the consumer spend the way that was anticipated."

Greek plunge: Greece's stock market sank 16 percent as it reopened from a month-long shutdown brought on by the near collapse of the country's financial system during its high-wire bailout negotiations.

A survey published Monday showed the damage caused to the Greek economy in July by the bank closures, money controls and uncertainty over the country's future.

Financial information company Markit said its gauge of manufacturing activity in Greece plummeted in July to the lowest reading ever recorded, despite improvements across the rest of the 19-country eurozone. A separate survey showed that business and consumer confidence fell for a fifth consecutive month in July to its worst level since October 2012.

Beef at Tyson Foods: Tyson Foods slumped $4.54, or 10.2 percent, to $39.81 after cutting its outlook for fiscal 2015 earnings. The meat producer, which owns the Jimmy Dean breakfast sausage brand, blamed conditions in the beef market for its woes, citing high cattle costs and "export issues," as factors that were hurting its profits.

Europe's day: Other European stock markets mostly rose as investors shrugged off the plunge in Greece. Asian shares closed lower on evidence of weakness in Chinese manufacturing. Germany's DAX rose 1.2 percent and France's CAC 40 gained 0.8 percent. Britain's FTSE 100 edged down 0.1 percent.

Manufacturing: A survey Monday showed that U.S. factories were a little less busy last month. The Institute of Purchasing Managers' manufacturing index slipped to 52.7 last month from 53.5 in June. Economists had expected the index to remain unchanged. Any reading above 50 indicates growth.

Investors are following this month's economic reports very closely to see if the economy is strengthening sufficiently for the Federal Reserve to raise interest rates later this year.

Currencies and bonds: The dollar strengthened to 124 yen from 123.91 yen Friday. The euro inched down to $1.0953 from $1.1010. Bond prices rose. The yield on the 10-year benchmark Treasury note fell to 2.15 percent from 2.18 percent Friday.

Metals: Gold fell $5.70 to $1,089.40 an ounce. Silver dropped 23 cents to $14.52 an ounce and copper declined 1.8 cents to $2.35 per pound.