Amazon.com failed to live up to lofty expectations for its Amazon Web Services cloud computing unit after rivals handily beat Wall Street forecasts.

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 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.