The Standard & Poor's 500 lost one point, or 0.1 per cent, to close at 2,000 Wednesday. The tech-dominated Nasdaq slid 25 points, or 0.6 per cent, to 4,572.
The Dow Jones industrial average edged up 10 points, or 0.1 per cent, to 17,078.
Apple fell 4.2 per cent after rival Samsung unveiled two smartphones at a trade show in Berlin. The unveiling comes less than a week before Apple is expected to reveal products.