While things are largely stable up on top of the list, Facebook founder Mark Zuckerberg dropped three spots and former New York mayor Michael Bloomberg rose by two.

According to the list announced Tuesday by Forbes, the riches of Bezos, 55, have swelled by $19 billion in one year and he is now worth $131 billion.

Bezos, who holds 16 percent of Amazon and whose wealth now makes him a target of the left wing of the US Democratic Party, has widened the money gap between himself and Gates, the philanthropist and co-founder of Microsoft.

Gates, 63, has seen his wealth grow to $96.5 billion, up from 90 billion last year, said Forbes.

Third place is held by Buffett, 88 and long considered an investment guru, although he did get stung in late February by a deep plunge in shares of US processed food maker Kraft Heinz, in which he had a large stake.

Buffett's fortune slipped by $1.5 billion to $82.5 billion, the magazine estimated.

It is more or less after this trio that things start to get shaken up on the Forbes list.

The CEO of French luxury good company LVMH, Bernard Arnault, held on to fourth place. But Zuckerberg lost $9 billion in net worth and slipped from fifth to eighth.

Ahead of Zuckerberg now are Mexican tycoon Carlos Slim, Zara and Inditex founder Amancio Ortega of Spain, and Oracle co-founder Larry Ellison.

Bloomberg rose from 11th to ninth place as his fortune increased to $55.5 billion, from $50 billion, said Forbes.

Americans still dominate the list with 14 of the top 20 billionaires from the US.