Stock index futures dipped last Thursday after three straight winning sessions as investors bet leaders at a euro zone summit will come up with a solution to the region’s debt crisis.

The European Central Bank is expected to cut interest rates and unveil a new package of bank aid later Thursday.

Market participants also looked for any hints the ECB will intensify its bond buying for the region’s struggling peripheral economies.

Despite choppy trade, Wall Street has risen for three straight days on optimism European leaders would agree on a decisive plan to fight the crisis at Friday’s EU summit.

If the meeting disappoints, stocks may give up gains of about nine per cent, reached since November 25. European stocks were little changed in light volume early Thursday.

S&P 500 futures fell 1.4 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time of expiration on the contract.

Dow Jones industrial average futures lost 11 points, and Nasdaq 100 futures sank 2.5 points. Late Wednesday, Standard & Poor’s warned it could cut the credit ratings of the European Union and large area banks if a mass downgrade of euro zone countries materialises.

The rating agency has said it may downgrade nearly all 17 euro zone countries if no solution emerges to solve the crisis.

Boeing’s biggest labour union ratified a four-year contract extension late Wednesday, ensuring a new version its 737 narrow body plane will be built in Washington state.