The major U.S. stock indexes ended Wednesday slightly higher after choppy trading. Investors took a wait-and-see approach ahead of the presidential debate and a key inflation report closely watched by Federal Reserve officials.

"We're in a holding pattern as we wait for Friday's PCE report for more data," said Michael Green, portfolio manager at Simplify.

Shares of chipmaker Nvidia (NVDA.O) rose 0.25%, ending the session higher after earlier losses. Large-cap names such as Apple (AAPL.O), Amazon (AMZN.O) and Tesla (TSLA.O) also saw their shares rise.

A flurry of economic data is due out this week, culminating in Friday's Personal Consumer Expenditures (PCE) price index, the Federal Reserve's preferred inflation gauge and a key driver of monetary policy decisions.

The Federal Reserve is forecasting one interest rate cut in December. However, investors are pricing in a 56.3% chance of a 25 basis point rate cut in September, according to LSEG's Interest Rate Probabilities app, and expecting about two cuts by the end of the year.

By 4 p.m., the Dow Jones Industrial Average (.DJI) was up 16.10 points, or 0.04%, to 39,128.26. The S&P 500 (.SPX) was up 8.61 points, or 0.16%, to 5,477.91, and the Nasdaq Composite (.IXIC) was up 87.50 points, or 0.49%, to 17,805.16.

"Investors are holding off for now, waiting for tomorrow's presidential debate and more economic data, especially Friday's PCE report," said Sam Stovall, chief investment strategist at CFRA.

Strong earnings reports and favorable inflation data could fuel a shift away from tech stocks and into sectors that have underperformed this year, according to Ryan Detrick, chief market strategist at Carson Group.

Investors have been flocking to non-tech sectors this week.

"We're likely to see continued volatility until we get a catalyst," said Brian Jacobsen, chief economist at Wealth Management.

Shares in appliance maker Whirlpool (WHR.N) rose 17.1% after news broke that German engineering group Robert Bosch may buy the company.

FedEx (FDX.N) shares soared 15.53% after the company announced that its fiscal 2025 profit forecast would beat expectations, sending the Dow Jones Transport (.DJT) to its highest level in more than a month.

Apple (AAPL.O) shares rose nearly 2% after analysts at Rosenblatt upgraded the iPhone maker's stock to buy from neutral. Meanwhile, Tesla shares rose 4.81% after Stifel began coverage of the company with a buy rating.

Amazon.com Inc's (AMZN.O) market value reached $2 trillion for the first time on Wednesday, becoming the fifth U.S. company to do so. Optimism about artificial intelligence and expectations of possible interest rate cuts this year have fueled demand for tech stocks.

Amazon shares rose 3.4% to $192.70, pushing the e-commerce giant's market value past $2 trillion. That puts it in line with tech giants Microsoft Corp (MSFT.O), Apple Inc (AAPL.O), Nvidia Corp (NVDA.O) and Alphabet Inc (GOOGL.O).

Shares of Amazon, which were added to the Dow Jones Industrial Average (.DJI) in February, have gained more than 26% year to date. In February, the company became the fifth-largest U.S. company by market value after Nvidia climbed one spot.

Amazon Web Services, the world's largest cloud services provider, has seen growth again after a slump last year, thanks to accelerated adoption of artificial intelligence technologies.

Amazon has also invested in AI startup Anthropic and robotics company Fig, looking to capitalize on the rapidly growing interest in artificial intelligence.

Late last year, Amazon unveiled a new generation of custom-designed data center chips that are aimed at machine learning and generative AI applications.

Shares of major U.S. banks including Morgan Stanley (MS.N), Citigroup (C.N) and Bank of America (BAC.N) fell ahead of the Federal Reserve's annual stress test results.

The broader S&P 500 (.SPSY) fell 0.47%.

Rivian (RIVN.O) shares rose 23.24% after German automaker Volkswagen (VOWG_p.DE) announced plans to invest up to $5 billion in the U.S. electric vehicle maker.

General Mills (GIS.N) shares fell 4.59% after the Cheerios cereal maker reported below-expected full-year profit and a bigger-than-expected drop in quarterly sales.

Declining stocks outnumbered advancing stocks on the New York Stock Exchange (NYSE) by a 1.41-to-1 ratio. Overall, the NYSE posted 106 new highs and 89 new lows.

The S&P 500 posted 10 new 52-week highs and 6 new lows, while the Nasdaq Composite posted 41 new highs and 171 new lows.

Trading volume on U.S. exchanges totaled 10.59 billion shares, below the 20-day average of 11.83 billion shares.