The S&P 500 was up 0.6% in midday trading to 2,182.99.

The Dow Jones Industrial Average was up 0.7% to 18,516.96.

The NASDAQ was up 0.5% to 5,243.80.

The yield on a 10-year Treasury bond was down 3.6% to 1.58%.

The price of gold was up 0.1% to $1,327.

RETAIL

Irvine-based Tilly’s Inc. is up 4.9% to $8.39 and a $239 million market cap. The youth apparel retailer’s shares are up about 22% since Wednesday’s positive quarterly report.

SERVICES

Anaheim-based Willdan Group Inc. was up 5.3% to $16.70 and a $139 million market cap on high volume. The engineering services company has signed new contracts recently to provide services to utilities in New York and California. Its shares have more than doubled year-to-date.

HEALTHCARE

Irvine-based Biolase Inc. was up 9% to $1.71 and a $99 million market cap. The dental laser maker had by midday traded shares at seven times its 90-day average; it share price is up about 115% year-to-date.