Amazon stock price

Jeff Bezos saw $13 billion of his fortune melt away after Amazon.com Inc.'s results left investors disappointed.

Shares of the e-commerce company slumped more than 8% in early New York trading on Friday as it reported a quarterly loss and the slowest sales growth since 2001. If the loss persists, Bezos’s net worth will drop to around $155 billion, according to the Bloomberg Billionaires Index. At his peak last year, he was worth more than $210 billion.