US stocks were caught in a holding pattern on Wednesday as investors braced for the Federal Reserve's long-awaited policy decision, with the size of the expected rate cut still the focus of debate.

Futures on the Dow Jones Industrial Average (YM=F) and S&P 500 (ES=F) rose roughly 0.1%, with record highs still within reach after a similarly muted close on Tuesday. Contracts on the tech-heavy Nasdaq 100 (NQ=F) also added 0.1%.

Stocks are ticking over as the market waits to find out how aggressive the Fed will be when it makes its first US interest-rate cut since 2020 at the end of its meeting later Wednesday.

The significant policy shift is widely expected, given growing signs the central bank has managed to cool inflation without severe harm to the economy. But investors are still guessing at whether hopes for a 0.5% cut will be fulfilled, or the historic pattern of 0.25% moves will repeat itself.

Read more: Fed predictions for 2024: What experts say about the possibility of a rate cut

In recent days, traders have stepped up bets on a bigger cut even after Fed officials earlier in September flagged they were more likely to trim the benchmark rate by 25 basis points. As of Wednesday morning, Fed Funds futures were pricing in a better than 60% chance the Fed goes large, up from just 15% odds a week ago.

Intense focus is also on the Fed's new interest rate projections, an indication of how many rate cuts officials expect to see in the rest of 2024 and in 2025. The so-called "dot plot" will come when the Fed releases its policy decision at 2 p.m. ET.

Meanwhile, investors absorbed developments in the tech sector. Microsoft (MSFT) and BlackRock (BLK) are teaming up on an effort to raise $30 billion to build out AI infrastructure, while Google parent Alphabet (GOOG) won its bid to overturn a $1.7 billion EU antitrust fine related to digital ads.