Bill Gates, the IT tycoon and philanthropist worth $66 billion, is the richest man in the US, according to the latest Forbes Rich List, with renowned investor Warren Buffett in second place, at $46 billion.

In third place is another giant of Silicon Valley, Larry Ellison, worth $41 billion; in fourth, is Charles Koch, at $31 billion, and fifth is his brother, David Koch, at $31 billion. The Koch brothers made their fortunes from diverse sources and are renowned, among other things, for their financial backing of political organisations and think tanks.

Members of the Walton family – owners of WalMart, make up sixth, seventh and eighth rankings in the list, while Michael Bloomberg, founder of the eponymous news vendor empire, and now mayor of New York, is in tenth place, Forbes said.