The economy doesn't seem to be a challenge for America's richest individuals. Billionaires are amassing wealth so quickly that they can't all fit on the Forbes list of 400 richest Americans; the minimum net worth to make the list is $1.3 billion.
"The numbers are staggering," Forbes magazine editor Randall Lane told CNBC. "There are 61 American billionaires who aren't even qualified to make the first 400." Combined, the wealth of the richest 400 individuals soared by 19 percent over the past year, to reach a record $2 trillion.
Forbes attributes the increased wealth to the bull stock market and improving real estate values. The average net worth of individuals on the list is $5 billion.
Microsoft founder Bill Gates maintained his spot at the top of the list of richest Americans for the 20th straight year, but this year he also claimed the title of richest person in the world. Gates' net worth of $72 billion is up by $6 billion from a year earlier and puts him ahead of Carlos Slim, the Mexican telecommunications tycoon who previously claimed the title.
The second-youngest billionaire on the Forbes list is 29-year-old Facebook founder Mark Zuckerberg, whose net worth of $19 billion puts him at No. 20. Dustin Moskovitz, whose net worth of $5.2 billion places him at No. 85, is a few days younger than Zuckerberg. He attained his wealth at Facebook, too.
Not all billionaires who retained their rank on this year's list made money -- 30 of them experienced a decline in wealth. No. 77 on the list, investor Ira Rennert, lost the most in dollars, taking a $1 billion hit on his fortune over the past year, leaving him with $5.5 billion. The biggest loser in percentage terms was developer Roger Wang, No. 166 on the list, who saw his fortune drop by 16.7 percent, to end up at $3 billion.
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