The S&P 500 was up 0.5% in midday trading to 2,713.90.
The Dow Jones Industrial Average rose 0.8% to 25,004.00.
The Nasdaq climbed 0.1% to 7,223.39.
The yield on a 10-year Treasury bond fell 1% to 2.91%.
The price of gold was flat at $1,332.
Alteryx Inc. (NYSE: AYX) in Irvine was up 17% to $34.45 and a $2 billion market cap. The data analytics software maker beat Wall Street expectations in a quarterly earnings report yesterday.
Sabra Health Care REIT Inc. (Nasdaq: SBRA) in Irvine was up 4.8% to $17.33 and a $3.1 billion market cap. The health facility owner said in a quarterly report yesterday it completed several actions in 2017 to grow, diversify and strengthen its balance sheet.