Will there be a trillionaire in the 21st century?

It is a matter of when, not if, according to many wealth experts. Steve Kraus, the chief insights officer of Ipsos MediaCT, which releases an annual survey on wealth, said he would not be surprised to see a trillionaire within the next 25 years.

Andrew Amoils, senior analyst at South Africa-based global affluence tracker New World Wealth dared to be even more specific. Taking into account variables including GDP per capita, wealth per capita, commodity price, exchange rate and price-earnings ratio forecasts—as well as the outlook in specific countries including the U.S., Russia and India—he said there is an 11 percent chance of a trillionaire within the next 25 years (with the U.S. being the most likely domicile, followed by India, which will see the greatest number of new millionaires created by 2039).

“This is a geometric trend. It’s not an incremental progression,” said Paul O’Brien, an Oxfam vice president who is studying the impact of wealth on global policy. “Existing wealth has a greater capacity to accumulate wealth. … If we are now at 37 individuals to reach a trillion, will we be down to five people in 2039, with $200 billion each, and 65 years from now, turn those five into one?”