The Nasdaq was down 0.48% to 3,005 in midday trading Friday, while the Dow Jones Industrial Average was off 0.49% to 13,167.
The S&P 500 fell 0.33% to 1,423.
The yield on a 10-year treasury bond was up 0.76% to 1.73%.
The price of gold was down 2.3% to $1,676 per ounce.
Shares of Anaheim drug maker Questcor Pharmaceuticals Inc. fell about 6% to $24 for a market value of $1.4 billion. Maryland-based competitor Cerium Pharmaceuticals received orphan status on its treatment for infantile spasms. Cerium is seen as a possible competitor in the U.S. to Questcor, which has its own infantile spasm treatment, Acthar gel.
Lake Forest-based Quantum Fuel Systems Technologies Worldwide Inc. was up about 18% to $0.73 for a market value of $35 million. The company said Thursday it will supply its natural gas storage systems to a truck equipment company for its fleet of natural gas trucks.