Forbes estimates Warren Buffett lost $10bn over the past year
The collective wealth of the richest 400 Americans has fallen by $300bn (£187bn) over the past year, according to the latest Forbes 400 rich list.
With downturn in the financial markets and wider economy taking its toll, this is an annual decline of 19%.
Out of the 400 people on the list, business magazine Forbes estimates that 314 saw their wealth decline.
It was only the fifth time since the Forbes 400 was first compiled in 1982 that the collective wealth has fallen.
RICHEST FIVE AMERICANS
1 Bill Gates, $50bn, down $7bn
2 Warren Buffett, $40bn, down $10bn
3 Lawrence Ellison, $27bn, unchanged
4 Christy Walton and family, Wal-Mart, $21.5bn, down $1.7bn
5 Jim Walton, Wal-Mart, $19.6bn, down $3.8bn
Source: Forbes 400
The second richest person on the list - celebrated investor Warren Buffet - saw the biggest financial decline over the past year, losing an estimated $10bn.
Meanwhile, disgraced financier Sir Allen Stanford has fallen off the list.
The assets at Sir Allen's banking empire have been frozen since the start of the year after he was accused of running an $8bn fraud.
Sir Allen has pleaded not guilty to the charges, and continues to be held in detention ahead of his trial.
Microsoft co-founder Bill Gates remains top of the list, worth an estimated $50bn.
Of the 10 richest Americans, third place Lawrence Ellison was the only one to see his wealth remain unchanged. He is worth an estimated $27bn.