(Reuters) – U.S. stock index futures tumbled on Friday as gloomy forecasts from megacaps Amazon and Apple heightened fears that the Federal Reserve’s aggressive interest rate hikes were finally slowing the economy and could hammer corporate earnings.

Amazon.com Inc joined a chorus of Big Tech firms that have disappointed investors this week by forecasting a slowdown in sales growth for the all-important holiday season and warned of a hit to consumers’ purchasing power. Shares cratered 13.6% in premarket trade.

Apple Inc cautioned revenue growth could see some pressure in the December quarter but shares edged 0.6% higher as the iPhone maker’s fourth-quarter results showed some resilience.

Shares of other megacap tech companies such as Microsoft, Google-parent Alphabet and Meta Platforms, which reported downbeat earnings earlier this week, were down between 0.4% and 1.3%. Their shares are down between 6% and 25% for the week.

Tech sector earnings were viewed as a major test of the strength of corporate America in the face of decades-high inflation and the dismal results have fed into fears of a looming recession from aggressive monetary policy tightening by the Federal Reserve.

While another 75 basis point rate hike from the Fed next week is largely priced in, traders are now waiting for a key U.S. inflation data due at 8:30 am ET to gauge whether the central bank could ease its pace of rate hikes in December.

The report is expected to show the Personal Consumption Expenditures Index (PCE), the Fed’s preferred inflation measure, climbed 5.2% on a year-over-year basis in September when stripped of volatile food and energy costs.

At 4:32 a.m. ET, Dow e-minis were down 97 points, or 0.3%, S&P 500 e-minis were down 30 points, or 0.79%, and Nasdaq 100 e-minis were down 130.75 points, or 1.16%.

A report on Thursday showing a rebound in U.S. economic growth in the third quarter had helped ease slowdown fears.

Twitter was set to be delisted from the New York Stock Exchange, a day after Tesla chief Elon Musk completed his $44 billion acquisition of the social media company. Arch Capital Group will replace Twitter on the S&P 500 from Nov. 1.

Shares of Tesla were down 1.1% premarket.

(Reporting by Amruta Khandekar; Editing by Sriraj Kalluvila)