The S&P 500 was up in 0.8% in midday trading to 2,447.80.
The Dow Jones Industrial Average was up 0.7% to 21,864.86.
The NASDAQ was up 1.1% to 6,283.32.
The yield on a 10-year Treasury bond was up 3 basis points to 2.21%.
The price of gold was down 0.5% to $1,291.
Impac Mortgage Holdings Inc. (NYSE: IMH) was up 3.4% to $13.59 and a $284 million market cap on above-average volume. The company is a residential mortgage lender.
ChromaDex Corp. (NYSE: CDXC) in Irvine was up 5% to $3.34 and a $154 million market cap. The maker of nutritional ingredients got a $5.1 investment—the third and final part of a $25 investment in the company by a Hong Kong billionaire.