Apple, Facebook Stocks Fumbled In The Wall Street

The dip in the social media company`s stock, along with a 1.7 percent slide in Apple, weighed on the S&P technology sector, which fell 1.37 percent.

Energy stocks held onto gains even after crude oil prices reversed course shortly after the market opened as traders booked profits.

Trade tensions continued to fester, with U.S. President Donald Trump on Monday making a veiled threat against the World Trade Organization. Also looming is a July 6 deadline when Washington is set to impose tariffs on $34 billion worth of Chinese goods.

"In the short term, company fundamentals are quite solid and the economy is strong," said Brant Houston, managing director at CIBC Private Wealth Management.

"But with the trade war looming there is a lot of uncertainty and a lot of unknowns. Until we get more clarity there it is difficult for investors to jump back into the equity market."

Shares of American Airlines, United Continental and Delta Air Lines fell between 1 percent and 2.28 percent after Deutsche Bank downgraded all three stocks saying the growing U.S.-China trade dispute could weigh on their results.

The Dow Jones Industrial Average declined 0.54 percent to end at 24,174.82 points, while the S&P 500 lost 0.49 percent to 2,713.22.

The Nasdaq Composite dropped 0.86 percent to 7,502.67.

With U.S. exchanges closing at 1 p.m. ET ahead of the July 4 holiday, volume was 3.9 billion shares, compared to the 7.1 billion average over the last 20 trading days.

As well as a day off, traders were looking toward June unemployment data due out on Friday for a glimpse of the how much the labor market may be tightening, and for potential price pressure.