(Reuters) -U.S. stock index futures traded flat to marginally higher on Wednesday as investors awaited a key inflation reading and a policy announcement from the Federal Reserve as it concludes its two-day meeting.

Markets have been broadly cautious this week, seeking clearer signs on the central bank's likely policy path, although a surge in Apple shares helped lift the S&P 500 and the Nasdaq to record closing highs for the second consecutive session on Tuesday.

Apple's shares edged down 0.5% in premarket trading. The tech giant had leapt over 7% to a record high close in the previous session, as investors cheered newly launched AI features in its devices.

With a market capitalization of $3.18 trillion as of Tuesday's close - just behind Microsoft - this latest spurt saw Apple firmly reclaiming its spot ahead of AI chip powerhouse Nvidia's $2.97 trillion in the race to become the world's most valuable company.

The Consumer Price Index report for May is expected at 8:30 a.m. ET, while the Fed's policy announcement is due at 2 p.m. ET.

"Today's CPI (and) the Fed meeting afterwards are being anticipated to such an extent that there's a lot riding on them... and we are perhaps overdue for a bit of a correction," said David Morrison, senior market analyst at Trade Nation.

May core inflation is expected to remain steady at 0.3% for the month and edge down to 3.5% year-over-year. Headline CPI on a monthly basis is forecast to fall to 0.1% from 0.3%.

"I think the market will be extremely happy if the numbers come in as expected, given that it is still sort of a bull market," Morrison said.

With rates overwhelmingly expected to remain unchanged, markets will focus primarily on the central bank's updated Summary of Economic Projections, particularly the "dot plot", which shows where policymakers expect interest rates to stand this year and in the long term.

While Wall Street has rallied in the past few months, much of these gains have been driven by megacap growth stocks and tech plays, causing some market participants to be concerned about the sustainability of equity strength, particularly if the Fed proves to be more hawkish.

While the S&P 500 technology index posted a record closing high in the last session, nine of its 11 major sectors were in the red, while the small-cap Russell 2000 fell 0.4%.

Markets now see a lower chance of the Fed's first rate cut in September, pricing in just over a 50% chance, according to the CME's FedWatch tool.

At 7:04 a.m. ET, Dow e-minis were up 46 points, or 0.12%, S&P 500 e-minis were up 7.25 points, or 0.13%, and Nasdaq 100 e-minis were up 26.75 points, or 0.14%.

Among single movers, Oracle gained 8.8% after forecasting double-digit revenue in fiscal year 2025 after the bell on Tuesday.

Paramount Global fell 2.1% after Shari Redstone, its largest shareholder, ended talks for a potential merger with David Ellison's Skydance Media, sources said.

The U.S. listing of electric-vehicle maker Nio slipped 3.1% after a report that the European Commission will apply extra duty on imported Chinese EVs.