NYSE
The Dow Jones Industrial Average plunged as much as 350 points Monday after U.S. oil prices tumbled to their lowest since 2009. Reuters/Carlo Allegri

U.S. stocks tumbled Monday, with the Dow Jones Industrial Average plunging as much as 350 points, after U.S. oil prices tumbled to their lowest level since 2009. Meanwhile, Brent crude, the global benchmark for oil prices, dropped below $55 a barrel for first time in more than five-and-a-half years.

During Monday’s trading session, the Dow, which measures the share prices of 30 large industrial companies, plunged 331.34 points, or 1.86 percent, to close at 17,501.65; the S&P 500 stock index lost 37.62 points, or 1.83 percent, to end at 2,020.58. The Nasdaq Composite fell 74.24 points, or 1.57 percent, to finish at 4,652.57.

West Texas Intermediate crude, the benchmark for U.S. oil prices, dropped 5 percent Monday to close at $50.04 a barrel on the New York Mercantile Exchange, its lowest price since April 2009. U.S. crude fell below $50 per barrel after the close. Brent crude dropped 6.22 percent Monday to $52.91 a barrel, for Feb. 15 delivery, on the London ICE Futures Exchange.

“We continue to see robust numbers from a supply standpoint coming out of Russia and Iraq, which led to Brent taking it on the chin and caused broad selling throughout the day,” said Dan Farley, investment lead for U.S. Bank wealth management. “Investors are concerned that it’s not just a supply fear. It’s growing worry about overall global growth and economic activity.”

Jeff Grossman, president of BRG Brokerage Inc., agrees. The drop in oil prices has been caused by a combination of factors, Grossman said, such as oversupply in crude inventories and bearish traders, causing fear in the financial markets. “Once everyone’s positive oil will go lower, we’ll go back up. We’re getting close to that area,” Grossman said from the NYMEX trading floor.

Another factor weighing on the global financial markets Monday was suspicion that the European Central Bank will announce more quantitative easing measures later this month to address concerns over the deflationary pressures that are currently gripping Europe. The euro sank to a nine-year low Monday, driven by concerns that Greece will abandon the Eurozone. The euro dropped to $1.19, its lowest value since December 2005.

Looking ahead on the economic calendar, most of the focus this week will be on the U.S. nonfarm payrolls report for December. The report, due out on Friday, is expected to show U.S. employers added 240,000 jobs in December, down from 321,000 in November, according to analysts polled by Thomson Reuters. The unemployment rate is expected to tick down to 5.7 percent last month after hovering around 5.8 percent in October and November. Average hourly earnings are forecast to increase 0.2 percent and hours worked is expected to hold steady at 34.6 per week.

“It’ll be very important to see if there’s wage growth. Last week, consumer confidence improved, but outlook was still somewhat cloudy. So seeing some wage growth will be important,” Farley said.

Here's the latest economic calendar for the week of Jan. 5. All listed times are EST.

Monday

9:45 a.m. -- ISM New York index (Dec.)

10 a.m. -- Motor vehicle sales (Dec.)

Non-U.S.:

Germany – Preliminary Consumer Price Index (Dec.)

Tuesday

9:45 a.m. -- Markit Services PMI (Dec.)

10 a.m. -- ISM nonmanufacturing (Dec.)

10 a.m. -- Factory orders (Nov.)

Non-U.S.:

Japan -- Markit Services PMI (Dec.)

China -- HSBC China Services PMI (Dec.)

United Kingdom -- Markit Services PMI (Dec.)

Wednesday

8:15 a.m. -- ADP employment (Dec.)

8:30 a.m. -- Trade deficit (Nov.)

2 p.m. -- FOMC minutes (Dec. 27 meeting)

Non-U.S.:

Germany -- Unemployment rate (Dec.)

European Union -- Consumer Price Index (Dec.)

European Union -- Unemployment Rate (Nov.)

Thursday

8:30 a.m. -- Weekly jobless claims

3 p.m. -- Consumer credit (Nov.)

Non-U.S.:

United Kingdom -- Bank of England interest rate decision

Friday

8:30 a.m. -- Nonfarm payrolls (Dec.)

8:30 a.m. -- Unemployment rate (Dec.)

10 a.m. -- Wholesale inventories (Nov.)

Non-U.S.:

China -- Trade Balance (Dec.)

China -- Exports (Dec.)

China -- Imports (Dec.)

Germany -- Industrial Production (Nov.)

Germany -- Trade Balance (Nov.)

Canada -- Unemployment Rate (Dec.)