The S&P 500 was down 0.22% to 1,512 in afternoon trading Monday.
The Dow Jones Industrial Average was off 0.13% to 13,983, while the Nasdaq was up 0.12% to 3,166.
The yield on a 10-year treasury bond fell 1.68% to 1.93%.
The price of gold rose 1.07% to $1,590 per ounce.
Shares of Newport Beach patent licensing company Acacia Research Corp. was up about 4% to $30 for a market value of $1.5 billion. The company last week reported better-than-expected results for the fourth quarter.
Tustin drug developer Peregrine Pharmaceuticals Inc. was down about 10% to $1, continuing a downward trend from last week as investors continue to be unimpressed with the latest update on its bavituximab cancer drug candidate. Peregrine had a recent market value of $188.2 million.