Amazon.com Inc. dropped in premarket trading after projecting weaker-than-expected operating income and trailing the sales growth of its cloud rivals, leaving investors searching for signs that the company’s huge investments in artificial intelligence are paying off.

The tech giant expects total net sales to be between $174.0 billion and $179.5 billion in the third quarter, compared with analysts’ average estimate of $173.08 billion.

Amazon.com shares AMZN.O fell 7% on Friday as the tech giant's results fanned investor fears its cloud unit was falling behind Microsoft and Alphabet in the artificial intelligence race.