Weight Watchers sank 5 per cent early Tuesday after Credit Suisse downgraded its rating on the stock, saying the company faces tough competition from free and low-cost weight loss applications.
The price of oil fell again a day after hitting a six-year low.
The Dow Jones industrial average fell 95 points, or 0.5 per cent, to 17,880. The Dow jumped 228 the day before.
The Standard & Poor's 500 index fell six points, or 0.3 per cent, to 2,074. The Nasdaq composite lost seven points, or 0.2 per cent, to 4,922.
Bond prices rose. The yield on the 10-year Treasury note fell to 2.07 per cent.