Wall Street seemed lethargic after the long Easter weekend, struggling to determine direction in an uneven session. 

Investors were most likely in pause mode ahead of a busy week of economic data and a jam-packed schedule of Federal Reserve speeches that could hint at when the next rate hike could come. 

The S&P 500 was up 0.05%, the Dow Jones Industrial Average rose 0.1%, and the Nasdaq dipped 0.14%. 

"Caution may be prevailing ahead of a heavy dose of domestic economic data this week and tomorrow's speech from Fed Chair Yellen, while a plethora of global markets remain closed today," said Nathan Peterson, senior derivatives analyst at the Schwab Center for Financial Research

Yellen is scheduled to address the Economic Club of New York on Tuesday and the critical March jobs report is due out on Friday. Manufacturing and construction data will also be released at the end of the week. 

Fed chatter was fueling some positive momentum on Monday. San Francisco Fed President John Williams struck a dovish tone, arguing that the current global environment is preventing the central bank from hiking rates sooner than later.

"The real issue is the global financial and economic developments, there's uncertainty about what's happening around the world and how that feeds back to the dollar and the U.S. economy," Williams told CNBC.

Williams' comments are in contrast to hawkish commentary from last week that increased the chances of a rate hike as soon as April. St. Louis Fed President James Bullard last week said that the economy continues to improve, noting that "the next rate increase may not be far off."

Oil pressured Wall Street on Monday as worries over supply and demand resurfaced. Crude fell 4.1% last week on signs a domestic supply glut is worsening, with inventories building by millions of barrels each week. West Texas Intermediate crude oil slid 0.2% to $39.39 a barrel on Monday. Despite the day's decline, crude is still off 13-year lows suffered earlier in the year.

"This seven-week rally has in large part been driven by a steady exit of short positions: speculators take profit from the twenty-month decline," Daniel Holder, commodity analyst at Schneider Electric, wrote in a note. "However, whether or not [crude's] $26.05 a barrel was in fact the low, this market has the potential to move back in that direction because the filled short positions have not been transformed into longs but instead into wait-and-see positions. The market now enters a period of price uncertainty."

Trading was also skittish after multiple reports late in the day of gunfire at a visitors center at Capitol Hill, prompting a lockdown of the building, surrounding area and the White House. The shooter is reportedly in custody. There have been no reports of casualties, though some have been injured. 

Wall Street was closed on Good Friday and reopened as normal on Monday morning. European markets were closed for the Easter Monday public holiday.

U.S. stocks snapped a five-week winning streak on Thursday amid renewed concerns about a crude-oil supply glut and global security worries following a terrorist attack in Belgium. For the week, the S&P 500 fell 1%, and the Dow dropped 0.6%. The losses were enough to pull stocks back into negative territory for the year.

"The five-week rally in the S&P 500 ran out of steam last week," explained David Joy, Ameriprise chief market strategist. "There was no steep selloff, nor was there strong downside volume, but stocks could not muster the strength to push higher. A firmer dollar and the Belgian terror attack took their toll on risk appetites in the shortened trading week."

Pending home sales in the U.S. reached a seven-month high. The number of houses for which a sale has been made but the deal not yet finalized climbed 3.5% in February, notching a reading of 109.1. Economists had expected pending home sales to climb by 1.8%.

Consumers both spent more and saved more in February, according to the latest data from the Commerce Department. Consumer spending rose 0.1% in February, in line with economists' estimates, but incomes climbed just 0.2%, the smallest increase since September. Meanwhile, the personal savings rate rose to a one-year high of 5.4%.

Revlon (REV) - Get Report sank after naming Fabian Garcia as its new CEO. The executive had previously headed operations at Colgate-Palmolive. The cosmetics company announced months ago that it was exploring strategic alternatives.

Pandora (P) tumbled 12% after Brian McAndrews resigned as CEO, effective immediately, after less than three years in the role. The company named founder Tim Westergren as its new CEO.

Starwood Hotels (HOT) climbed 2% after Chinese company Anbang Insurance Group raised its buyout offer. Marriott International (MAR) - Get Report has offered a separate merger proposal, which was initially accepted before Anbang expressed interest.

Batman vs. Superman, a production of Time Warner's (TWX) Warner Bros., topped the weekend box office, pulling in $170.1 million in North American sales and $254 million overseas. Analysts estimated the film needs to generate more than $800 million in total to break even.

Qlik Technologies (QLIK) jumped 9% on reports it is exploring strategic alternatives, including a possible sale. The data analytics company is currently under pressure from hedge fund Elliott Management, which disclosed an 8.8% stake earlier this month.