The S&P 500 was up 0.8% in midday trading to 2,276.33.
The Dow Jones Industrial Average was up 0.7% to 19,942.19.
The NASDAQ was up 1.3% to 5,484.89.
The yield on a 10-year Treasury bond fell 0.4% to 2.47%.
The price of gold fell 0.5% to $1,160.
Irvine-based Western Digital Corp. was up 3.3% to $68.47 and a $19.6 billion market cap. Shares in the storage products maker rose as investment analysts described the company’s plans to cut $800 million in operating expenses.
Irvine-based Endologix Inc. was down 9.3% to $6.25 and a $517 million market cap. The maker of medical devices to treat abdominal aortic aneurysms said the European Union would suspend the CE Marking for its AFX system because of reports of Type III endoleaks with a prior generation of the device.