The major benchmarks were virtually unchanged after half an hour of trading, although results from The Coca-Cola Company (NYSE:KO) fell flat.
The fizzy drinks maker fell almost 5% to $44.39 as it blamed the strength of the dollar for the fourth consecutive quarter in which sales fell.
The blue-chip measure, the S&P 500, was more or less unchanged at 2,101, as was the mid-cap S&P 400, at 1,476, and the small cap gauge, the Russell 2,000, at 1,140.
Hansen Medical, Inc (NASDAQ:HNSN) was the best performer on Nasdaq as it agreed to be bought out by Auris Surgical Robotics in an $80mln deal worth $4 a share.
The shares of the medical devices maker rose 40% to $3.98.
Oculus Innovative Sciences, Inc (NASDAQ:OCLS) matched that rise, advancing 40% to $1.3101 after the dermatology specialist said it had received new 510(k) clearance from the US Food and Drug Administration for the company's new Microcyn-based Lasercyn gel.
It was all happening in the medical sector in early dealings as OncoSec Medical Incorporated (NASDAQ:ONCS) shot up 21% to $2.916 after it presented long-term, follow-up data of patients who were treated with its investigational therapy ImmunoPulse IL-12 and later went on to receive an anti-PD-1/PD-L1 therapy.
The results suggested that the cancer treatment may prime and enhance response rates of the body's immune system.
It was not all happy days in the sector, however, as Argos Therapeutics, Inc (NASDAQ:ARGS) lost almost a quarter of its value as it revealed its chief operating officer, Fred Miescowicz, will leave the company on Friday having served notice to quit last week.
Argos announced major staff cutbacks on Tuesday as it seeks to cut back on running costs.