The Nasdaq was up 0.25% to 3,186 in midday trading Wednesday, while the Dow Jones Industrial Average rose 0.41% to 13,621.
The S&P 500 was up 0.36% to 1,465.
The yield on a 10-year treasury bond fell 1.38% to 1.79%.
The price of gold was up 0.07% to $1,773 per ounce.
Shares of Anaheim-based Questcor Pharmaceuticals Inc. fell about 37% to $32 after an online newsletter said insurer Aetna Inc. of Hartford, Conn., planned to limit coverage of the drug maker’s Acthar Gel. Questcor had a market value of about $2 billion.