As per Bloomberg Billionaires Index, the world's 400 wealthiest individuals shed $19 billion in 2015.
The downfall happened owing to lowering of commodities prices and signs of a slower-growing China.
Bloomberg reported that world’s richest person, Mexican telecommunications mogul
Slim fell to No. 5 this year after losing almost $20 billion.
Meanwhile, Microsoft co-founder
Ortega, Europe's richest person since June 2012, leapfrogged Slim and Buffett as he rose $12.1 billion to $73.2 billion. His 20 percent rise was still $19 billion short of the increase for the year's top-gainer, Amazon.com founder Jeff Bezos.
Bezos added $31 billion in 2015, undoing the $7.4 billion decline he had in 2014 and propelling him up 16 positions to No. 4 on the index.