The S&P 500 fell 0.54% to 1,459 in midday trading Monday.

The Dow Jones Industrial Average was down 0.54% to 13,363, while the Nasdaq was off 0.32% to 3,092.

The yield on a 10-year treasury bond fell 0.84% to 1.90%.

The price of gold was off 0.27% to $1,644 per ounce.

Irvine-based healthcare software maker Quality Systems Inc. rose about 5% to $18 for a market value of $1.1 billion. Quality Systems subsidiary NextGen Healthcare Information Systems LLC said it has partnered with healthcare products maker and distributor Medline Industries Inc. The two companies will help market some of each other’s services and products to their respective customer bases.

Anaheim-based drug maker Questcor Pharmaceuticals Inc. rose about 4% to $27 for a market value of $1.6 billion.

Irvine dental laser maker and distributor Biolase Inc.’s shares jumped about 25% to $2.50, after the company said it expects its fourth-quarter guidance to top $18 million. Biolase, which had a recent market value of $78 million, had previously said it expected fourth-quarter revenue to be between $16.5 million and $17.5 million.

Shares of Tustin-based drug developer Peregrine Pharmaceuticals Inc. shot up about 80% to $2.42 for a market value of $310 million. Roth Capital Partners raised its rating of the company’s stock from “neutral” to “buy” after Peregrine said that its September announcement related to a discrepancy in the results of its lung cancer drug candidate bavituximab affected only the one-milligram dose of the drug. The findings had no impact on the three-milligram dosage of bavituximab.

Santa Ana-based for-profit school operator Corinthian Colleges Inc. fell about 7% to $2.60 for a market value of $222 million.