(Read more: Billionaire Sara Blakely says secret to success is failure)
Another casino mogul, Lui Chee Woo, who controls Macau casino operator Galaxy Entertainment, ranked at number nine, tacking $8.3 billion onto his personal fortune, bringing his net worth to $19.6 billion, according to Wealth-X. In March, Forbes ranked him at only the 98th richest person globally, but his earnings may leapfrog him into the top 40.
All in, billionaires have had a good year.
In November, Wealth-X and UBS Global Billionaire Census for 2013 found billionaires' combined fortunes have grown by $226 billion in the past year alone. They have more than doubled to $6.5 trillion from $3.1 trillion in 2009 and the group expanded by 810 over the period to 2,170 members, the census found.
(Read more: Asia's billionaire club grows as Europe's shrinks)
Their total wealth is now larger than the gross domestic product of any country except the United States and China, and could fund the U.S. budget deficit until 2024, the census found.
The average billionaire spends $22 million on yachts, $16 million on private planes and $14 million on art, according to the census.
In the U.S., the wealthy are now hoarding their highest proportion of assets in nearly a hundred years.
The top 1 percent's share at the end of 2012 was equal to 50.4 percent of the U.S.'s overall wealth, a level higher than any other year since 1917 and surpassing 1928, the peak of stock market bubble in the "roaring" 1920s, according to Emmanuel Saez, a professor of economics at the University of California, Berkeley.
Since the financial crisis of 2008, the top 1 percent of incomes have grown by 31.4 percent while the bottom 99 percent of incomes has grown only by 0.4 percent, he said.
—By CNBC.Com's Leslie Shaffer; Follow her on Twitter @LeslieShaffer1