The S&P 500 was off 0.31% to 1,780.99 in afternoon trading Tuesday.
The Dow Jones Industrial Average fell 0.12% to 15,865.34, while the Nasdaq slipped 0.11% to 4,025.06.
The yield on a 10-year Treasury bond was down 0.80% to 2.85%.
The price of gold was off 1.25% to $1,228.90 per ounce.
Mission Viejo-based nursing home operator Ensign Group Inc. was down about 2% to $44.03 for a market value of $968.84 million. The company said Monday its board approved a 7.7% increase in the quarterly cash dividend to $0.07.
Irvine-based CombiMatrix Corp. shares sank about 21% to $2.25 for a market value of $10.66 million.
The company announced the pricing of a $12 million public offering on Tuesday.
Irvine-based disk drive maker Western Digital Corp. continued its rise from Monday, up about 3% to $84.02 for a market value of $19.86 billion. The company closed up about 2% yesterday. JPMorgan Chase & Co. upgraded the company's stock from "neutral" to "overweight" on research showing that the move to flash-based memory in PCs from hard disk drives is not happening as quickly as originally expected.