The S&P 500 was down 0.4% in midday trading to 2,334.89.
The Dow Jones Industrial Average was down 0.5% to 20,496.22.
The NASDAQ was down 0.3% to 5,818.53.
The yield on a 10-year Treasury bond fell 2.7% to 2.23%.
The price of gold rose 0.9% to $1,289.
Del Taco Restaurants Inc. was up 3% to $12.62 and a $488 million market cap. Shares have recovered most of their 5% decline from earlier this week after negative comments circulated in stock forums that questioned the fast food chain’s financial reporting.
Biolase Inc. was up 6% to $1.36 and a $92 million market cap. The dental laser maker said it would raise up to $17.6 million from a private placement of convertible preferred shares and warrants with current investors.