The S&P 500 fell 0.2% in midday trading to 2,384.41.
The Dow Jones Industrial Average was down 0.2% to 20,941.10.
The NASDAQ declined 0.2% to 6,048.67.
The yield on a 10-year Treasury bond rose 0.2% to 2.30%.
The price of gold rose 0.2% to $1,268.
Mission Viejo-based Ensign Group dropped 8.6% to $17.47 and a $900 million market cap. The company is scheduled to report first-quarter earnings on May 1.
Lantronix Inc. fell 14% to $2.84 and a $50 million market cap. The Irvine-based maker of Internet of Things and IT products yesterday reported third-quarter revenue rose 16% to $11.5 million. Its shares have climbed about 66% this year.