Stock index futures dropped on Friday as disappointing results from Microsoft Corp and American Express Co sparked caution one day after the Dow industrials <.DJI> closed above the key 9,000 mark.

S&P 500 futures shed 0.2 of a point and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract, and Nasdaq 100 futures fell 2.25 points. Dow Jones industrial average futures edged up 18 points.

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