The S&P 500 was up 0.5% in midday trading to 2,141.04.
The Dow Jones Industrial Average was up 0.7% to 18,265.35.
The NASDAQ was up 0.8% to 4,995.95.
The yield on a 10-year Treasury bond was up 4.3% to 1.43%.
The price of gold was down 0.1% to $1,357.
Lake Forest-based Del Taco Restaurants Inc. was up 4.8% to $9.44 and a $361 million market cap. The fast food chain began an exchange offer—common stock for warrants—to reduce the number of outstanding warrants.
Irvine-based Impac Mortgage Holdings Inc. was down 4.8% to $16.83 and a $207 million market cap on above-average volume. The company is a residential mortgage lender.