Stock index futures extended gains on Friday after data showed U.S. gross domestic product for the second quarter was revised lower, but the figure was better than anticipated.

S&P 500 futures rose 8.1 points and were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures gained 68 points and Nasdaq 100 futures added 15.25 points.

U.S. second quarter GDP was revised lower to an annual rate of 1.6 percent versus expectation of 1.4 percent.

(Editing by Jeffrey Benkoe)