No. 1: United States

Bloomberg News

No. 1: United States

2009 Population: 306.8 million*

2009 number of millionaire households: 4,715,000**
Percentage increase: 15.1 percent YOY**
Share of country’s wealth held by millionaire households: 56 percent**

Even though the U.S. real estate market remained weak, the stock market rebound helped boost the number of millionaire households 15.1 percent in 2009. The U.S. had the most millionaires by far, leading second-in-line Japan by 3,485,000 households. Millionaires represented a fraction of the U.S. population last year but held 56 percent of its wealth, according to Boston Consulting Group.

* Source on all slides: Population Reference Bureau
** Source on all slides: Boston Consulting Group. The year on year change in number of millionaire households was calculated using a constant exchange rate; BCG used yearend 2009 exchange rates to calculate the number of millionaire households in both 2008 and 2009.