The Nasdaq was up 1.53% to 2,937.60 in midday trading, while the Dow Jones Industrial Average rose 0.97% to 13,013.11.

The S&P 500 was up 1.26% to 1,377.17.

The yield on a 10-year treasury bond was up 6.86% to 1.5%.

The price of gold was nearly flat at $1,616.50 per ounce.

Shares Aliso Viejo-based networking-equipment maker QLogic Corp. were down about 14% to $10.79 a share, for a market value of about $1 billion. QLogic yesterday reported revenue and profit in line with prior guidance, but said it expects a slowdown in IT spending in addition to weaker server and storage unit sales for the industry for the year.

Shares of Costa Mesa-based networking electronics maker Emulex Corp., a competitor of QLogic, were down by about 6% to $6.03, for market value of about $522 million.

Shares of Irvine-based medical device maker Endologix Inc. were down nearly 10% to $12.53, and a market value of about $725 million after it missed Wall Street expectations on earnings.

Irvine-based biotechnology company CombiMatrix Corp. shares were up nearly 17% to 83 cents, and a market value of about $9 million.