Wall Street shares edged lower on Wednesday closing lower for the fourth successive session with about 60% of traded stocks on the NYSE falling amid concerns over the Federal Reserve monetary policy and its scale-back. The Standard & Poor's 500 Index declined 0.13% to 1,792.81, the Dow Jones industrial average fell 0.16% to 15,889.77 and the Nasdaq Composite Index added 0.02% to 4,038.00.