The S&P 500 was up 0.7% in midday trading to 2,078.85.
The Dow Jones Industrial Average was up 0.6% to 17,870.92.
The NASDAQ was up 0.6% to 4,802.03.
The yield on a 10-year Treasury bond was up to 1.85%.
The price of gold was up 0.5% to $1,297.
Irvine-based restaurant chain Habit Restaurants Inc. was up 3% to $17.25 and a $245 million market cap in anticipation of the company releasing its first quarter report on Wednesday. Analysts expect Habit to report revenue of $67.7 million for the quarter and earnings of 9 cents per share.