The S&P 500 was up 0.7% in midday trading to 2,007.27.

The Dow Jones Industrial Average was up 0.6% to 17,048.23

The NASDAQ was up 0.7% to 4,740.75.

The yield on a 10-year Treasury bond was up 3.8% to 1.90%.

The price of gold was up 0.6% to $1,266.

TECHNOLOGY

Newport Beach-based Clean Energy Fuels Corp. was down 4% to $3.30 and a $297 million market cap. The builder and operator of natural gas fueling stations reported an annual loss.

RESTAURANTS

Costa Mesa-based El Pollo Loco Holdings Inc. was up 4% to $14.31 and a $548 million market cap. The fast food chain had traded shares at an above-average rate as it prepares to report results next week.

RETAIL

Anaheim-based Pacific Sunwear of California Inc. was up 16% to 22 cents and a $15 million market cap. The teen apparel and accessories retailer hired an investment bank and a restructuring firm as $160 million in debt is set to come due later this year.

HEALTHCARE

Irvine-based CombiMatrix Corp. was up 21% to $5.31 and a $5 million market cap on high volume. The DNA-testing company had traded shares by midday at about five times its 90-day average.