The S&P 500 fell 0.12% to 1,877.28 in afternoon trading Wednesday.
The Dow Jones Industrial Average was down 0.05% to 16,505.51, while the Nasdaq was off 0.61% to 4,136.07.
The yield on a 10-year Treasury bond slipped 1.39% to 2.69%.
The price of gold rose 0.19% to $1,283.50 per ounce.
Irvine-based healthcare software maker Quality Systems Inc. was off about 5% to $14.88 for a market value of $895.92 million. Morgan Stanley lowered its rating on the company's stock from "equal weight" to "underweight."
Irvine-based Pacific Premier Bancorp Inc. was off about 7.5% to $14.93, despite reporting first-quarter net income and asset growth. Pacific Premier had a recent market value of $257.15 million.