STORY: Wall Street's main indexes closed with modest gains on Wednesday, as investors held their cards close to their vests ahead of a presidential debate and a key inflation report.

The Dow and S&P 500 both edged into the green, while the Nasdaq gained half a percent.

Economic data this week includes Friday's personal consumption expenditures, or PCE, price index, the Federal Reserve's preferred inflation gauge.

Adam Phillips, managing director of investments at EP Wealth Advisors, said core PCE - which strips out volatile food and energy prices - should indicate the central bank is moving closer to cutting interest rates.

"The market is expecting the month-over-month inflation print for core PCE to be up about 1/10 of a percent. If so, that's going to be the lowest print all year on a year-over-year basis. Inflation could be at about 2.6%, so the lowest in a few years. So, this is expected to be a very Fed-friendly inflation report."

The Fed has been projecting only one interest rate cut this year, in December. But investors see a more than 50% chance of a rate cut in September, according to LSEG.

Stocks on the move included Amazon, which rose nearly 4% to bring the company's market value above $2 trillion, the fifth U.S. company to cross that level.

Among other megacaps, Apple rose 2% and Tesla gained 4.8%.

FedEx shares jumped 15.5% after the delivery giant forecast fiscal 2025 profit above estimates.

And shares of Whirlpool surged 17% after Reuters reported that German engineering group Robert Bosch is weighing a bid for the U.S. appliances maker.