U.S. stock index futures showed a subdued performance on Wednesday, as investors awaited the release of the U.S. July Personal Consumption Expenditures (PCE) price index and NVIDIA's second-quarter earnings report after market close. S&P 500 futures edged down 0.1%, Nasdaq 100 futures fell 0.2%, and Dow Jones Industrial Average futures rose 0.01%.

The PCE price index, the Federal Reserve's preferred measure of inflation, is due to be released at 8:30 AM ET. Economists expect the index to have risen 0.1% month-over-month and 3.6% year-over-year in July. Additionally, Brent crude oil prices fell more than 2% to $85.10 per barrel, with a cumulative decline of over 9% for the week.