The S&P 500 (INDEXSP:.INX) is down today with companies to release quarterly earnings today include Anadarko Petroleum Corporation (NYSE:APC) and Eastman Chemical Company(NYSE:EMN). Among significant movements Sprint Nextel Corporation (NYSE:S) the most active stock and Southwestern Energy Company (NYSE:SWN) are up today while Alpha Natural Resources, Inc. (NYSE:ANR) is suffering largest fall. Data provided by…