The S&P 500 was up 0.2% in midday trading to 2,877.09.
The Dow Jones Industrial Average was down 0.1% to 25,879.88.
The Nasdaq was up 0.1% to 7,909.83.
The yield on a 10-year Treasury bond was 0.1% lower at 2.94%.
The price of gold was 0.1% higher to $1,201.
Foundation Building Materials Inc. (NYSE: FBM) in Tustin rose 3.3% to $14.07 and a $604 million market cap. It distributes building products, including wallboard and ceiling systems.
Endologix Inc. (Nasdaq: ELGX) in Irvine plunged 10% to $1.98 and a $168 million market cap. Shares in the maker of a device to treat abdominal aortic aneurysms have dropped about 70% since a 52-week high in June.