The S&P 500 was flat in midday trading at 2,159.69.
The Dow Jones Industrial Average was up 0.1% to 18,241.99.
The NASDAQ was down 0.1% to 5,303.12
The yield on a 10-year Treasury bond fell 0.6% to 1.55%.
The price of gold fell 0.4% to $1,325.
Newport Beach-based Terra Tech Corp. was up 8.4% to 37 cents and a $129 million market cap on above-average volume. The maker of hydroponic growing equipment and other products for the cannabis market last week began to ship herbs and flowers from its Edible Garden subsidiary to the 89-store Wegmans Food Markets Inc. grocery store chain based in Rochester, N.Y.
Irvine-based Lombard Medical Inc. was down 8.3% to 91 cents and an $18 million market cap on above-average volume. The maker of endovascular stent-grafts to repair aortic aneurysms last month reported a loss in its most recent quarter and said it would exit the U.S. market.