Amazon.com Inc. shares have largely climbed on the back of two trends: strength in its cloud business and a focus on costs. Now both could be in question.

The pressure is on Amazon.com to deliver on lofty expectations for cloud computing in its fourth-quarter results on Thursday, after Microsoft and Google's lackluster reports jolted investor faith in Big Tech's billion-dollar investments in AI.

An independent inquiry report has told the UK’s competition watchdog to consider investigating AWS and Microsoft’s cloud services.