Stock index futures trimmed gains on Monday following data that showed manufacturing in New York State contracted for the third month in a row in August.

S&P 500 futures rose 5.8 points and were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration of the contract. Dow Jones industrial average futures gained 30 points, and Nasdaq 100 futures added 7.75 points.