Stock futures rose slightly as traders debated how big the Fed's expected rate cut would be: Live Update

Stock futures rose slightly on Wednesday as Wall Street expected the Federal Reserve to cut interest rates for the first time in four years. Gains were muted as uncertainty lingered over how big the easing from the central bank would be.

The future is bound Dow Jones Industrial Average Added 51 points, or 0.1%. S&P 500 futures And Nasdaq-100 Futures advanced 0.2% and 0.3% respectively.

The Fed is expected to deliver its latest policy decision at 2 pm ET. The central bank is expected to cut rates by at least a quarter of a percentage point, but traders are divided on how big the cut will be. CME Group's FedWatch tool rates traders between a 65% chance of a half-point cut and a 35% chance of a quarter-point move.

It's unusual for the Fed's decision to have so much uncertainty because the central bank usually tries to telegraph its next move. Traders believed for much of last month that the Fed would cut by a quarter point, but the idea of ​​a super-sized cut began to gain traction last week.

“You have to go back more than 15 years to find an uncertain situation so close to the conclusion. A lot of money will be made and lost today,” Jim Reed, Deutsche Bank's head of global economics and thematic research, wrote in a Wednesday note.

With the S&P 500 after an 18% gain this year, a stagnant economy is expected to shore up and further boost an already strong market. Historically, the benchmark has averaged about 16% gains in the 12 months following the first Fed rate cut in a cycle, according to data from Canaccord Genuity.

Wall Street saw that coming off a mixed session S&P 500 0.03% gain after another all-time high mark during intraday trading. D Dow Jones Industrial Average When lost about 16 points Nasdaq Composite Added 0.2%.