Stock index futures fell sharply on Friday after employment data showed a surprise decline in job creation last month, suggesting the impact of mortgage-market turmoil is taking a toll on the economy.

S&P 500 futures were off 10.3 points, below fair value, a formula to evaluate pricing taking into account interest rates, dividends and time to expiration on the contract.

Dow Jones industrial average futures lost 73 points, and Nasdaq 100 futures fell 14.5 points.

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