NEW YORK - This year, for the first time, a mere $1 billion in net worth is not enough for inclusion on Forbes magazine's list of the 400 richest Americans.
The new threshold - $1.3 billion, up $300 million from last year - kept 82 of America's billionaires off the rankings released yesterday.
Collectively, the people on the list are worth $1.54 trillion, compared with $1.25 trillion last year.
The names at the very top were unchanged: Microsoft Corp. founder Bill Gates led for the 14th straight year, this time with a net worth estimated at $59 billion.
He was followed by Warren Buffett of Berkshire Hathaway Inc. in second place with an estimated $52 billion, and casino mogul Sheldon Adelson, No. 3 with an estimated worth of $28 billion.
Larry Ellison, of Oracle Corp., maintained his ranking at No. 4, with an estimated net worth of $26 billion.
But the list showed some notable changes.
Joining the top 10 for the first time were Google Inc. founders Sergey Brin and Larry Page, tied for fifth place. The 34-year-old moguls' wealth has quadrupled since 2004 to an estimated $18.5 billion this year, on a 500 percent surge in their company's stock value.
Surging oil prices also helped some members of the list. Oil baron brothers Charles and David Koch broke into the top 10, sharing the No. 9 spot with estimated wealth of $17 billion. Their ascension bumped the Walton family, heirs to the Wal-Mart Stores Inc. fortune, from the top 10 for the first time since 1989.
Climbing 19 rungs to No. 7 was casino tycoon Kirk Kerkorian, who doubled his net worth to an estimated $18 billion. The 90-year-old investor is a majority shareholder in MGM Mirage - operator of the MGM Grand, Bellagio and other casinos - which posted record profits at several of its Las Vegas hotel-casinos.
Rounding out the top 10 was Michael Dell of computer maker Dell Inc., who was No. 8 with an estimated $17.2 billion.
Almost half of the 45 newcomers to the 400 made their money in hedge funds and private equity investments. The youngest member of this year's list was 33-year-old hedge fund manager John Arnold, who joined the ranks at No. 317 and a net worth of $1.5 billion.
The magazine confirmed the worth of an individual's holdings in public companies by using the Aug. 31 closing stock price, and estimated the value of private companies by evaluating comparable public firms in the industry.
The list also takes into account philanthropic donations.