* Futures up: Dow, S&P 0.3 percent, Nasdaq 0.4 pct
By Ryan Vlastelica
NEW YORK, Sept 30 (Reuters) - U.S. stock index futures were modestly higher on Tuesday, indicating a rebound from the previous session's decline as investors once again used a pullback as a buying opportunity.
* Market volatility has surged of late, with the S&P 500 posting closing moves greater than 0.5 percent in five of the past six sessions. Earlier this month, the benchmark index went 14 sessions without such a move, its longest such streak since 1995, according to MKM Partners. The CBOE Volatility index , a measure of investor anxiety, climbed by more than a third in September.
* Despite the outsized moves, the S&P has largely been range-bound between 2,011.36, its record closing level hit earlier this month, and 1,976.76, its 50-day moving average, which it has not closed under for more than one session since mid-August. The S&P is about 1.7 percent away from its record close.
* The range has come as investors use market declines as buying opportunities. The S&P has not had a correction, defined as a 10 percent decline from its peak, since 2012.
* For the month of September, the Dow is down 0.2 percent, the S&P is down 1.3 percent, and the Nasdaq is down 1.6 percent. For the third quarter, the Dow is up 1.4 percent, the S&P is up 0.9 percent, and the Nasdaq is up 2.2 percent. Both the S&P and Nasdaq are on track for their seventh straight quarterly advances.
* Investors continue to keep a close eye on the situation in Hong Kong, where thousands of pro-democracy activists protested against the Chinese government. The Hang Seng Index fell 1.3 percent, having declined in 15 of the past 18 sessions.
* While the economic impact to the tension is unknown, investors have paid close attention to the rate of growth in China. If the protests continue for an extended period, that may add to concerns about the country's prospects.
* Investors are also looking ahead to data on consumer confidence, seen essentially flat at 92.5 in September, and the Chicago purchasing managers index, which is expected to fall to 61.9 from 64.3 in August. Both reads are due at 10 a.m. (1400 GMT).
* An hour before those datapoints, the July S&P/Case-Shiller report on home prices will be released and is seen showing flat growth.
Futures snapshot at 6:47:
* S&P 500 e-minis were up 5.75 points, or 0.29 percent, with 120,352 contracts changing hands.
* Nasdaq 100 e-minis were gaining 15.75 points, or 0.39 percent, in volume of 22,126 contracts.
* Dow e-minis were up 51 points, or 0.3 percent, with 16,556 contracts changing hands. (Editing by Lisa Von Ahn)