The S&P 500 rose 0.2% in midday trading to 2,815.61.
The Dow Jones Industrial Average declined 0.1% to 25,783.36.
The Nasdaq was up 0.2% to 7,659.66.
The yield on a 10-year Treasury bond 0.4% higher to 3.17%.
The price of gold dropped 0.3% to $1,228.
Del Taco Restaurants Inc. (Nasdaq: TACO) dropped 8% to $10.05 and a $385 million market cap. The fast food chain revised full-year guidance downward in its most recent quarterly report.
Foundation Building Materials Inc. (NYSE: FBM) was down 3% to 11.17 and a $480 million market cap. Shares in the construction materials distributor have fallen about 25% year-to-date.