As of 2018, there is a grand total of 198,342 ultra high net worth individuals (UHNWIs) globally with assets over US$30 million, according to the most recent edition of Knight Frank’s Wealth Report.

Where are the billionaire in the future?
Expected number of UHNWIs in 2023 for the Top 10 Cities

Singapore will be rank #2 by 2023, with an expected total of 4,393 high net worth residents. Shanghai and Beijing could be cities to watch for decades to come, as they add millionaires and billionaires at a faster rate than any of the other heavyweights.
Who will be the fastest growing cities?
Here are the 10 cities that are expected to add UHNWIs the fastest between 2018-2023:

Not surprisingly, the fastest growth in UHNWIs over the next 5 years will come from Asian countries.