1. Gloomy markets: The good times can't last forever.
The losses weren't dramatic, however. The biggest loser was the Nikkei in Tokyo, which fell by 1.4%.
2. State of the Union: President Trump will speak to the nation during his State of the Union address on Tuesday.
Some companies have cheered the government's tax overhaul by announcing investments and giving bonuses and raises to employees.
Investors will also be listening for an outline of the president's infrastructure plan.
3. Stocks to watch -- MetLife, Thomson Reuters, JPMorgan: Shares in MetLife were down 7% premarket on worries about the company's business operations.
The insurer said in December that it had lost track of potentially tens of thousands of customers to whom it owed pension and annuity payments, and was trying to track them down.
MetLife postponed its fourth quarter earnings release on Monday, saying that the U.S. Securities and Exchange Commission had asked for more information on the matter.
The company has attributed the problem to "a material weakness in internal control over financial reporting."
Thomson Reuters is in focus after the company confirmed that asset management firm Blackstone Group is in talks to take a stake in its financial and risk unit.
JPMorgan Chase boss Jamie Dimon revealed Monday that he'll stay at the helm of America's largest bank for about five more years.
4. Earnings: Aetna, Harley-Davidson, McDonald's, Pfizer, Philips and T. Rowe Price will release earnings before the open.
Electronic Arts and Fidelity National will follow after the close.
5. Confident consumers: The U.S. Conference Board reveals its latest monthly consumer confidence index at 10 a.m. ET.
The American economy has added new jobs for 87 consecutive months and unemployment is at its lowest level in 17 years. That could explain why consumer confidence is extremely high.
European consumer confidence figures will also be released, alongside preliminary GDP figures for the final quarter of 2017.
6. Yellen's farewell: On Tuesday and Wednesday, Janet Yellen will oversee her final Federal Reserve meeting. She'll relinquish her post to Jerome Powell on February 3.
Powell is likely to continue slowly lifting interest rates as the economy improves.
7. Coming this week:
Tuesday -- State of the Union; Earnings from Harley-Davidson, McDonald's, Aetna, Pfizer and Electronic Arts
Wednesday -- Earnings from Anthem, AT&T, Microsoft, eBay, PayPal, Mondelez and Facebook
Thursday -- Earnings from Apple, Alphabet, Amazon, Time Warner, Hershey, UPS, MasterCard, Visa, Mattel, DowDuPont and ConocoPhillips
Friday -- U.S. monthly jobs report
- Stocks sink; State of the Union; MetLife trouble
- White House lawn troubles sink in
- Amazon stock sinks following Trump's attacks
- Stocks drop; Tech pain; Trouble at Facebook
- Trade war fears; Facebook trouble; Stocks up
- MetLife dealing with fallout over missing pension customers
- Netflix sinks 9% on a bad day for tech stocks
- Asia stocks sink after Wall Street's Christmas Eve plunge
- Bitcoin sinks 20%
- Stocks plunged. That doesn't mean the economy is in trouble.