While the e-commerce giant beat predictions on earnings per share, it missed on revenue, reporting $56.6 billion versus $57.10 billion analysts anticipated in a survey by Refinitiv. The drop represents a $70 billion loss in market cap, allowing Microsoft to pass Amazon in market cap.
It's Amazon's worst day since Jan. 29, 2016.
The company reported weaker-than-expected guidance for the holiday season, which gave analysts some pause. Amazon expected $2.1 billion to $3.6 billion in fourth-quarter operating income, well below Street estimates of $3.9 billion.
Still, Amazon's cloud computing business and nascent advertising business seem to be faring well. Amazon Web Services reported $2.1 billion in operating income for the quarter, beating FactSet estimates of $1.82 billion. In its "other" category, which is mainly made up of Amazon's advertising business, the company reported $2.5 billion in net sales.