5 countries that gained the most millionaires

The world's millionaires are migrating like never before—creating new megahubs of wealth and shifting the balance of money around the globe.

According to a report from New World Wealth, the U.K. was the top destination in the world for migrating millionaires over the past decade. Between 2003 and 2013, the U.K. had a net inflow of 114,100 millionaires (people with $1 million or more excluding their primary residence).

That was more than twice the gain of the number two ranked country, Singapore.

Singapore, with its tax-friendly policies and security, ranked second in attracting the world's wandering wealthy. It gained 45,000 millionaires between 2003 and 2013. The U.S. ranked third, gaining 42,400 millionaires.

So where were all these millionaires moving from? Mostly China. According to the report, China had a net outflow of 76,200 millionaires during the 10-year period. India was the next largest loser, with a net outflow of 43,400, followed by France, Italy and Russia.

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The report said Chinese millionaires were mostly moving to Hong Kong, Singapore and the U.K. Indian millionaires prefer the U.K., U.S. and Australia, while French and Italian millionaires were largely flocking to the U.K. and Switzerland.

A surprising number of Swiss millionaires are also moving—mostly to Singapore, the U.K. and the United Arab Emirates.

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The study said that overall, London has the most millionaires of any city, with 339,300. New York ranks second with 300,100, followed by Tokyo (226,500) and Singapore (225,000).

Here is the list of countries that gained the most millionaires between 2003 and 2013 and their net gain in millionaires.