U.S. stocks opened lower on Friday, continuing what has been a rough week for investors. The blue-chip Dow Jones Industrial Average opened the session down 0.7%, the S&P 500 was off 0.7% and the Nasdaq Composite Index was down 0.9% at the opening bell. Slumping oil prices continue to weigh on investor sentiment with prices for the commodity on track for their seventh-consecutive weekly decline. The West Texas front-end contract was down 6.2% at $51.27. Energy-related stocks including Marathon Oil Corp. Читать дальше...