The S&P 500 was down 0.5% in midday trading to 2,162.92.
The Dow Jones Industrial Average was down 0.6% to 18,493.37.
The NASDAQ was down 0.4% to 5,069.22.
The yield on a 10-year Treasury bond was down 1% to 1.56%.
The price of gold was up 0.6% to $1,327.
Lake Forest-based Del Taco Restaurants Inc. was up 14% to $11.19 and a $425 million market cap. The fast food chain report net income of about $5 million on revenue of $100 million in its most recent quarter. Both were up in the year-over-year period and both exceeded Wall Street expectations.
Irvine-based Habit Restaurants Inc. was up 4.5% to $17.17 and a $480 million market cap on high volume. The fast casual burger chain is scheduled to report earnings Aug. 3.