Things are improving for US billionaires with more than half of them adding to their net worth in a year which once again saw Bill Gates as the richest of them all, Forbes magazine has said.
Gates, founder of Microsoft, was the richest person in the US for the 17th year in a row with an estimated worth of $54 billion, up $4 billion from last year. Number two on the list was investor Warren Buffett, worth $45 billion, up $5 billion.
Oracle founder Larry Ellison's net worth was unchanged, in third place, at $27 billion. Christy Walton, heir to Walmart founder Sam Walton's fortune, was in fourth place with $24 billion, up $2.5 billion.
In stark contrast to the 2009 Forbes 400 list, 217 of the tycoons are now worth more than they were a year ago. Just 84 of the billionaires had a decrease in wealth. In 2009, a whopping 314 members of the exclusive club had experienced a decrease in their wealth.
The top 10 gained $24.9 billion this year. The same group had shed almost $40 billion last year.
The Forbes 400 are worth a combined $1.37 trillion, compared with $1.27 trillion last year. The price of admission to the list is back up to $1 billion from 2009 when $950m was enough to make the top 400.
There are no new entries or drop-offs in the top 10 but the list shuffled.
The Koch brothers, heads of energy and manufacturing giant Koch Industries, now rank above three other members of the Walton family and New York Mayor Michael Bloomberg, founder of news and information company Bloomberg LP, who round out the top 10.
Facebook's Mark Zuckerberg, number 35, saw the largest relative increase, more than tripling his fortune to $6.9 billion from $2 billion. Fellow Facebook co-founders Dustin Moskovitz and Eduardo Saverin join the list with fortunes of $1.4 billion and $1.15 billion, respectively.
Born just eight days after Zuckerberg, 26-year-old Moskovitz is the world's youngest billionaire.
The oldest tycoon on the list is David Rockefeller Senior, 95, worth $2.4 billion. Media magnate Oprah Winfrey comes in at number 130 and is one of 42 women on the list.
Car heir William Ford Senior made the list for the first time since 2005, at the 385th spot with $1 billion after Ford Motors Co's stock rose 50% and hit a five-year-high.
California is the state with the most billionaires - 83 - among them number 332 Meg Whitman, worth $1.2 billion, the Republican candidate for governor of the state in November elections.
