A surge in after-hours trading for Amazon.com added US$3,3bn to the fortune of Jeff Bezos, putting him less than $5bn away from becoming the world’s richest person.

Bezos saw his fortune surpass $80bn (R1,1 trillion) for the first time, according to the Bloomberg Billionaires Index.

The 53-year old has added $65,2bn to his net worth since the index debuted in March 2012 and ended Thursday with a net worth of $79bn. His net worth will surpass $80bn on the index for the first time if the gains hold on Friday.

Amazon shares added almost $50 after the company projected sales that may beat estimates in the current quarter, furthering an unbroken 20-year streak of double-digit revenue growth.

Amazon had first-quarter sales of $35,7bn and earnings of $1,48/share, beating Wall Street analyst expectations. Shares closed at $918,38 on Thursday and reached as high as $965 after hours.

The rise for Bezos beat the after-hours gains seen by Google co-founders Larry Page and Sergey Brin. The pair added $1,4bn when shares of Google parent Alphabet rose as high as $938,18 on news that the smartphone ad business helped Alphabet post revenue of $20,1bn and net income of $7,73/share.

Page is now worth $44,7bn and Brin $43,7bn, the 11th- and 12th-richest people in the world on Thursday.

Microsoft co-founder Bill Gates has been number one on the Bloomberg index since 17 May 2013. His fortune slipped $200m to $87,1bn after hours as Microsoft presented mixed results and slowing tablet sales growth. — (c) 2017 Bloomberg LP