The S&P 500 was down 0.5% in midday trading to 2,868.81.
The Dow Jones Industrial Average declined 0.6% to 25,868.23.
The Nasdaq dipped 0.1% to 7,827.50.
The yield on a 10-year Treasury bond plunged 4.5% to 1.66%.
The price of gold was 2.2% higher to $1,517.20.
The price of oil fell 4.9% to $51.03.
Irvine-based HCP Inc. (NYSE: HCP) rose 2.3% to $33.54 and a $16.7 billion market cap. Shares of the health facilities REIT have climbed 6.4% since July 31 when it reported second quarter funds from operations topped the average analyst estimate.
San Clemente-based glaucoma device maker Glaukos Corp. (NYSE: GKOS) declined 4.1% to $73.21 and a $2.7 billion market cap. The company is scheduled to report second quarter results today after the market closes.
Axonics Modulation Technologies Inc. (Nasdaq: AXNX) rose 10% to $33.96 and a $1 billion market cap. After the the Irvine-based maker of medical devices to treat urinary disorders reported second-quarter results, the shares yesterday fell to as low as $30.05, an 11% drop. Then the GuruFocus.com website revealed that Chief Executive Raymond Cohen yesterday purchased $106,000 worth of shares at an average price of $30.41 each.