Bezos replaced the tech pioneer as the world’s richest person – but could be relegated to second again if the shares fall back.
If the 1.6% increase holds until the New York Stock Exchange closes, Mr Bezos’ net worth will be $90.6bn (£69.3bn) , compared to Gates’ $90.7bn (£69.23bn) .
As recently as June, Mr Bezos’ wealth suffered a setback when his company’s share price fell more than 3%, wiping $2.6bn (£2bn) off his net worth.
While both men remain extraordinarily rich – with a combined value of over $180bn (£137.39bn) – it will mark the first time since May 2013 that Gates, 61, has not sat atop the billionaires list.
Mr Bezos, 53, founded Amazon.com in 1994 and initially operated the company from his garage. He retains a 17% stake in the company which has increased its value by 40% this year.
In June, he invited direct comparison with Mr Gates by asking people on Twitter to help him with ideas for philanthropy .
Alongside his wife, the Microsoft founder runs the Bill and Melinda Gates Foundation – one of the largest philanthropic organisations in the world, with an endowment trust fund of $44bn (£39.6bn) . It employs more than 1,400 people.
The foundation has promised to spend all of its resources within 20 years of both of the Gates’ deaths.
