U.S. stocks closed lower on Monday, putting the Dow Jones industrial average into the red for the year. Airlines were among the biggest decliners as investors worried that expanding capacity could hurt their profits.
The Dow Jones industrial average fell 82.91 points, or 0.5 percent, to 17,766.55.
The Standard & Poor's 500 index lost 13.55 points, or 0.7 percent, to 2,079.28.
The Nasdaq composite fell 46.83 points, or 0.9 percent, to 5,021.63.
For the year:
The Dow is down 56.52 points, or 0.3 percent.
The S&P 500 index is up 20.38 points, or 1 percent.
The Nasdaq is up 285.57 points, or 6 percent.