The S&P 500 was up 0.4% in midday trading to 2,102.57.
The Dow Jones Industrial Average was up 0.5% to 17,722.10.
The Nasdaq was flat at 5,093.73.
The yield on a 10-year Treasury bond was up 1.8% to 2.29%.
The price of gold was down 0.2% to $1,093.
Irvine-based Edwards Lifesciences Corp. was down 3% to $151.40 and a $16.3 billion market cap. The heart valve maker was up in early trading by about 3% on a generally strong quarterly report but investors by midday put more emphasis on an 80% decline in earnings per share to $1.02 in its second quarter.
Huntington Beach-based Quiksilver Inc. was down 6.5% to 49 cents and an $83 million market cap. The surfwear maker has reportedly hired Peter J. Solomon Co. to help it restructure, with one area being an increase in its credit line. Quiksilver had about $48 million in cash on hand as of April.