The S&P 500 was down 0.4% in midday trading to 1,982.10.
The Dow Jones Industrial Average was down 0.5% to 16,918.42.
The NASDAQ was down 0.5% to 4,652.68.
The yield on a 10-year Treasury bond was up 2% to 1.93%.
The price of gold was up 0.8% to $1,267.
Irvine-based Biolase Inc. was up 30% to $1.23 and a $72 million market cap. The dental laser maker reported higher quarterly and annual revenue yesterday after markets closed. Its quarterly loss narrowed though its annual losses were slightly higher.
Newport Beach-based Alliance Healthcare Services Inc. was down 3% to $7.84 and an $83 million market cap. The radiation clinic operator is expected to release results today after markets close.