The S&P 500 was up 0.1% in midday trading to 2,184.09.

The Dow Jones Industrial Average was flat at 18,570.20.

The NASDAQ was up 0.2% to 5,237.47.

The yield on a 10-year Treasury bond was down 2% to 1.53%.

The price of gold was up 0.6% to $1,356.

TECHNOLOGY

Newport Beach-based Clean Energy Fuels Corp. was up 7% to $4.36 and a $572 million market cap. The operator of natural gas fueling stations was trading at a rate twice its 90-day volume this morning, and is up by about 30% since it’s deal last week to supply natural gas upgrades to Columbus, Ind.-based Cummins Inc., a Fortune 500 engine maker.

HEALTHCARE

Irvine-based CombiMatrix Corp. was up 8% to $3.53 and an $8 million market cap. The DNA-testing and diagnostic company said this week that insurer Health Care Service Corp. in Chicago, a Blue Cross and Blue Shield provider in several states, would reimburse for certain chromosomal analyses for which CombiMatrix tests and, separately, said Universal Diagnostic Laboratories in Van Nuys will market and distribute the same test.