* S&P may be poised for third straight weekly decline

* Consumer sentiment data on tap after market open

* FXCM (NYSE: FXCM – news) rallies in premarket after strong results

* Futures up: Dow 6 pts, S&P 0.25 pt, Nasdaq 2.5 pts (Updates prices)

By Ryan Vlastelica

NEW YORK, March 13 (Reuters) – S&P Futures were little changed on Friday as investors held off on making bets following a volatile week that was marked by sharp swings in both directions.

The benchmark S&P 500 posted its biggest one-day gain since early February on Thursday, a rally that offset the biggest one-day loss since early January on Tuesday.

Equities have recently been driven by the U.S. dollar, with the S&P having a high inverse correlation to the currency. Thursday’s equity rally corresponded with the biggest one-day drop in the U.S. dollar index in a month.

The dollar index has risen almost 2 percent this week, and is on track for a fourth week of gains. Investors see the continued strength in the greenback as a threat to multinational corporate profits. The index rose 0.1 percent on Friday.

Wall Street has also been focused on when the Federal Reserve will raise interest rates, with some strong economic data recently suggesting the first hike could come as early as June. Higher rates tend to raise borrowing costs for companies and individuals and crimp spending, though strong indicators are seen as better for the market in the long term.

Trading could be volatile ahead of next week’s Fed meeting, when the central bank could provide further insight into when the first rate increase will come.

A preliminary read on March consumer sentiment will be released after the market opens, with the University of Michigan Surveys of Consumers seen essentially holding steady with the previous report.

Crude oil fell 1.7 percent, which could weigh on energy names. The commodity has fallen in six of the past seven sessions.

Walt Disney Co will be in focus after the company said it had started work on a sequel to “Frozen,” the best-selling animated movie of all time. Shares (Berlin: DI6.BE – news) rose 0.5 percent to $ 107.70 in premarket.

FXCM Inc jumped 15 percent to $ 2.48 in heavy premarket trading a day after the company reported fourth-quarter earnings that beat expectations. This was the currency broker’s first quarterly report since the removal of the cap on the Swiss franc sparked massive losses that pushed it to take a rescue loan.

The Dow is on track for a weekly rise of 0.2 percent while the Nasdaq is on track for a drop of 0.7 percent. The S&P is down 0.3 percent on the week, and if the benchmark index ends negative for the week, that will mark its third straight weekly decline. Still, Thursday’s rally lifted the Dow and S&P back into positive territory for 2015, and the S&P is 2.4 percent from its record closing high.

Futures snapshot at 7:40 a.m. EDT (1140 GMT):

* S&P 500 e-minis were up 0.25 point, or 0.01 percent, with 92,048 contracts changing hands.

* Nasdaq 100 e-minis were up 2.5 points, or 0.06 percent, in volume of 9,952 contracts.

* Dow e-minis were up 6 points, or 0.03 percent, with 7,825 contracts changing hands. (Editing by Bernadette Baum)