The S&P 500 fell 0.65% to 1,587.16 in afternoon trading Wednesday.
The Dow Jones industrial average was down 0.65% to 14,742.88, while the Nasdaq was off 0.75% to 3,303.71.
The yield on a 10-year Treasury bond fell 3.46% to 1.62%.
The price of gold was down 1.91% to $1,444.10 per ounce.
Irvine drug maker Allergan Inc.'s shares slumped about 13% to $98.84 on its lowered full-year financial forecast. Allergan had a recent market value of $29.49 billion.
Shares of Irvine medical device maker Endologix Inc. fell about 5% to $14.25 after missing analyst estimates on its first-quarter profit. Endologix had a recent market value of $899.08 million.
Mission Viejo-based Ensign Group Inc. fell about 3% to $33.89, for a market value of $741.88 million. Ensign operates healthcare facilities, hospice companies and home health businesses and said today it acquired Omaha Nursing Center on undisclosed terms.
Newport Beach chipmaker Mindspeed Technologies Inc.'s shares surged 17% to $2.69 on news that the company hired Morgan Stanley to assist with the company’s analysis of its “strategic alternatives.” The company also reported a lower-than-expected loss for the March quarter. Mindspeed had a recent market value of $110.5 million.