Andy Jassy
Amazon Web Services CEO Andy Jassy.
  • Amazon shares fell 5% Friday after the company warned about future revenue growth in its cloud division.
  • That erased an earlier rally after-hours Thursday that could've added $135 billion in valuation to the tech giant.
  • CFO Brian Olsavsky said some Amazon Web Services customers were cutting their costs in preparation for a potential economic slowdown.

Amazon's stock price fell Friday after a gloomy forecast about future growth in its cloud division wiped out an earlier post-earnings rally.

Shares were down 5% to under $105 at around 5 a.m. Eastern Time, having previously jumped as much as 12% in after-hours trading Thursday.