The Global Wealth report from Boston Consulting Group said the number of millionaires in the world grew to 17 million in 2014, up from 15 million in 2013. The world's millionaires controlled 41 percent of the $164 trillion in global private wealth, up from 40 percent in 2013. The report said millionaires are expected to control 46 percent of the world's wealth in 2019.
The growing fortunes of the wealthy are owed largely to rising stock markets and asset prices around the world. It said, 73 percent of the gains in global private wealth last year came from market performance on existing assets rather than newly created wealth or businesses.
"The wealthier are getting more and more wealthy," said Anna Zakrzewski, partner and managing director for Boston Consulting Group. "They have a much larger share of their wealth invested in equity markets and last year was a good year for market performance."
The U.S. still has by far the largest number of millionaires. The population of millionaires in the U.S. grew by 4.7 percent last year to 6.9 million. (BCG defines millionaires as households with $1 million in easily monetized wealth-cash, stock and securities, pension funds and other financial assets. Their wealth measurement doesn't include real estate, business ownership and collectible and consumer goods).
China ranked second in millionaire population but had the largest number of new millionaires in 2014. Its millionaire population grew to 3.6 million from 2.4 million in 2014, meaning China added more than half of the world's 2 million new millionaires last year.
Ranking third was Japan, with 1.1 million millionaires, up 4.7 percent from 2013.
Switzerland had the highest concentration of millionaires, or millionaires per capita. Fully 13.5 percent of Switzerland's population are millionaires. Bahrain ranked second, with 12.3 percent, followed by Qatar with 11.6 percent.
The report also highlighted growing divide between the rich and the super rich, as billionaires and those with hundreds of millions of dollars enjoy stronger wealth gains than mere millionaires.
The number of ultra-high-net-worth households, which it defines as $100 million and up, is expected to grow by 19 percent globally and 12 percent in North America by 2019.
In contrast, the number of "lower high-net worth" households, or those with $1 million to $20 million, is expected to grow by only 6.9 percent.