U.S. stocks open lower after Greece deal

U.S. stocks opened slightly lower on Monday after last week's big rally, amid Greek concerns and expectations of Federal Reserve Chair Janet Yellen's remarks over the next two days.

Greece won some time and breathing space after bridging arrangement was reached on Friday with its eurozone creditors. The progress pushed away scenarios of an imminent Grexit, but more tough challenges lie ahead.

In order to secure the financial lifeline, Greece must present a list of reform proposals on Monday.

Wall Street also focused on Yellen's semi-annual testimony to Congress on Tuesday and Wednesday. Although many consider last week's Fed minutes as dovish, some analysts believe Yellen will likely imply that a June rate hike is still on the table.

In corporate news, HSBC reported that profit before tax for 2014 was 18.7 billion U.S. dollars, down 17 percent from 2013. Shares dropped over 5 percent in the early trading.

"2014 was a challenging year in which we continued to work hard to improve business performance while managing the impact of a higher operating cost base," said Chief Executive Stuart Gulliver.

Apple announced a plan to spend 1.9 billion dollars to build two new European data centers, one in Ireland, and the other in Denmark. The plan is the company's largest investment ever. Shares gained 0.55 percent on early Monday.

Shortly after the opening bell, the Dow Jones Industrial Average shed 69.2 points, or 0.38 percent, to 18,071.24. The S&P 500 fell 4.16 points, or 0.2 percent, to 2,106.14. The Nasdaq Composite Index was down 2.8 points, or 0.06 percent, to 4,953.16.

U.S. stocks surged Friday, with both the Dow Jones Industrial Average and the S&P 500 refreshing their record highs, as the euro zone and Greece reached an agreement over a four-month extension to its bailout. Endi