Futures for the Dow Jones Industrial Average dropped 250 points, or 0.58%. S&P 500 futures slipped 0.6%, while Nasdaq futures fell 0.61%. The yield on the 10-year Treasury surged 4.6 basis point to 4.485% after Moody's downgraded the U.S. credit rating one notch late Friday to Aa1 from AAA, the highest grade.

Stock index futures fell sharply on Monday after Moody’s Ratings decision to strip the U.S. of its last remaining top-tier credit score. S&P 500 futures (SPX) -1.3%, Nasdaq 100 futures (US100:IND) -1.

U.S. stock index futures declined Sunday evening following Moodys downgrade of the U.S. credit rating, raising concerns over mounting debt and economic uncertainty. The ratings agency lowered the sovereign credit