 Here's the Wall Street Business Report. Stocks closed lower, extending a slump that left Wall Street with its worst week since April. The S&P 500 fell 7 tenths percent, its third straight drop since setting a record high on Tuesday. The Dow sank 9 tenths percent and the Nasdaq Composite lost 8 tenths percent. The losses came as businesses around the world scrambled to contain the effects of a disruptive technology outage.