The S&P 500 was up 0.4% to 3,295.68 in midday trading.
The Dow Jones Industrial Average rose 0.1% to 27,172.36.
The Nasdaq increased 0.8% to 10,864.96.
The yield on a 10-year Treasury bond decreased 1% to 0.66%.
Oil climbed 0.15% to $39.37 a barrel.
The price of gold was down 0.13% to $1,908 an ounce.
Orange County’s publicly traded medical device makers and drugmakers were mixed in midday trading. Irvine-based Edwards Lifesciences Corp. (NYSE: EW) fell 4.9% to $78.28 a share with a $48.6 billion market cap while Evolus Inc. (Nasdaq: EOLS) in Newport Beach climbed 11.7% to $3.92 per share for a market cap of $132 million.
Irvine-based Montrose Environmental Group Inc. (NYSE: MEG) rose 7.5% to $24.04 per share for a market cap of $570 million. Shares in the air quality and environmental services company have risen about 60% since its July 23 IPO at $15 a share.