The S&P 500 was up 0.56% to 1,978.64 in midday trading Monday.
The Dow Jones Industrial Average also was up 0.78% to 17,075.90.
The Nasdaq was up 0.71% to 4,447.03.
The yield on a 10-year Treasury bond inched up 0.83% to 2.54%.
The price of gold fell 2.27% to $1,307.10 per ounce.
Share of Anaheim-based Questcor Pharmaceuticals Inc. were up 3.8% on an update on its merger agreement with Dublin-based Mallinckrodt plc. Questcor said it will hold a shareholder meeting on August 14 to consider approval of the $5.6 billion deal. The transaction is expected to be completed in August. Questcor recently had a market capitalization of $5.9 billion.
Shares of Aliso Viejo-based QLogic Corp. were up 1.6% Monday, buoyed by a rating upgrade on Friday by Morgan Stanley. The boost from “underweight” to “equal weight,” which initially sent QLogic’s stock up more than 4%, was on expectation that the networking equipment maker’s server unit will see accelerated growth into 2015. QLogic had a recent market capitalization of $924 million.
Huntington Beach-based Quiksilver Inc. is up 3%, to a market capitalization of $581 million. The action sports apparel company recently signed licensing agreements for several of its products, including its Roxy brand of girls’ clothing, as well as its line of beach-related accessories. Separately, analysts are projecting Quiksilver would be an attractive acquisition target for Greensboro, N.C.-based apparel company V.F. Corp.