Stocks opened mostly flat on Wednesday, following five straight days of losses as investors continued to fret about the economic outlook.

A weak revenue outlook from Ciena Corp and mixed May sales data from McDonald's Corp added to the cautious tone in the market.

McDonald's, a Dow component, fell 1.3 percent to $80.11 while Ciena slumped 11 percent to $21.47.

The Dow Jones industrial average <.DJI> was down 2.88 points, or 0.02 percent, at 12,067.93. The Standard & Poor's 500 Index <.SPX> was down 0.63 points, or 0.05 percent, at 1,284.31. The Nasdaq Composite Index <.IXIC> was down 8.12 points, or 0.30 percent, at 2,693.44.

(Reporting by Ryan Vlastelica; Editing by Padraic Cassidy)