Stock index futures held gains on Tuesday after a report showed U.S. home prices were unchanged in October, ending five straight months of increases.

S&P 500 futures rose 4.2 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 added 32 points, and the Nasdaq 100 futures gained 4.50 points.

Home prices in 20 metropolitan areas was flat in October after rising a revised 0.4 percent in September, according to Standard & Poor's/Case-Shiller indexes.

(Reporting by Edward Krudy; editing by Jeffrey Benkoe)