* Further upside seen as limited after recent gains
* Trading volume expected to be light in holiday week
* Investors looking to data on consumer confidence
* Futures down: Dow 25 pts, S&P 5.25 pts, Nasdaq 6.75 pts
By Ryan Vlastelica
NEW YORK, Dec 30 (Reuters) - U.S. stock index futures were slightly lower on Tuesday, suggesting the market's recent trend of slight moves and low volume would continue in the final trading days of the year.
* Equities have recently trended to the upside, buoyed by strong economic data and the U.S. Federal Reserve's commitment to be "patient" about raising interest rates. After the S&P 500 gained nearly 6 percent over the prior eight sessions, it notched its 53rd record close of the year on Monday, while the Dow just barely missed extending its streak of positive sessions to eight.
* The speed and scale of the rally could cap further upside, especially in a holiday week, when many market participants are out. Volume is expected to remain light, which could exacerbate volatility. The stock market will be closed on Thursday for New Year's Day.
* A pair of data releases could drive the day's trading. A measure of consumer confidence, which will be released at 10 a.m. (1500 GMT), is seen rising to 93 in December, from the previous reading of 88.7. Investors will also be paying attention to CaseShiller data on home prices, released at 9 a.m. Prices are seen up 0.4 percent in October.
* While overall trading has been light of late, there has been heavy volatility in both the biotech and energy sectors. That trend could continue on Tuesday, with Gilead Sciences one of the premarket session's most active names. The stock is down 0.2 percent at $97.13. Crude oil is down 0.1 percent, having fallen about 2 percent in each of the three previous sessions.
* For the month of December, the Dow is up 1.2 percent, the S&P is up 1.1 percent and the Nasdaq is up 0.3 percent. For the fourth quarter, the Dow is up 5.8 percent, the S&P is up 6 percent and the Nasdaq is up 7 percent.
* Both the S&P and Nasdaq are on track for their eighth straight quarterly gain, the longest for the S&P since 1998 and the longest for the Nasdaq since 1996.
* For 2014, the S&P is up 13 percent and the Nasdaq is up 15 percent in the third straight annual gain for both. The Dow is up 8.8 percent and on track for its sixth straight positive year. Utilities are the strongest sector of the year, up almost 30 percent, while the energy sector is the weakest, down 8.7 percent.
Futures snapshot at 6:42:
* S&P 500 e-minis were down 5.25 points, or 0.25 percent, with 54,368 contracts changing hands.
* Nasdaq 100 e-minis were down 6.75 points, or 0.16 percent, in volume of 8,402 contracts.
* Dow e-minis were down 25 points, or 0.14 percent, with 8,910 contracts changing hands. (Editing by W Simon)