Bill Gates has become the first US$50 billion man, overtaking the Sultan of Brunei as the world's richest person.
His net worth jumped 40 per cent from a year ago to US$51 billion (HK$394 billion), an increase of US$475 per second.
Microsoft chairman Mr Gates, 43, who is fighting an anti-trust lawsuit brought by the US Government, topped Forbes magazine's rankings of the world's richest people for the fourth year in a row.
The magazine excludes dictators and royalty, but had the sultan been on the list, he would have held top spot until this year.
Between them, Mr Gates and fellow Microsoft executives Paul Allen and Steven Ballmer have amassed US$82.7 billion - US$25.1 billion more than Hong Kong's fiscal reserves.
Five Hong Kong moguls made the top 50; property tycoons Lee Shau-kee and Li Ka-shing came ninth and 13th with respective fortunes of US$12.7 billion and US$10 billion.