Amazon shares slid after the online-retail and cloud-services giant offered a first-quarter outlook that came up short of Wall Street’s expectations while forecasting bumpy trends in its cloud business.

Amazon's beat Wall Street's overall expectations with $187.8 billion in net sales, up 10%, and came in well ahead on the bottom line, with earnings of $1.86 per share, vs. expectations of $1.48 for the fourth quarter.

The company called out an ‘unusually large, unfavorable impact’ from currency, which is expected to hit first-quarter results.