NEW YORK - The number of U.S. millionaires increased by 600,000 in 2010, according to a report by Spectrem Group.
About 8.4 million American households had assets of $1 million or more, not including their primary residences, a gain of 8 percent, according to Chicago-based Spectrem. The figure is still below the 2007 high for millionaires, when there were 9.2 million in the United States, Spectrem said.
"The recovery is doing better in this population, probably better than for Main Street America," said George Walper Jr., president of Spectrem, in a telephone interview. The Standard & Poor's 500 index returned 15 percent last year.
The figure is lower than pre-financial-crisis levels because the value of real estate has not recovered, he said. The survey includes the value of second homes and real-estate investments. In December the S&P/Case-Shiller index of home values in 20 cities was down 31 percent from its peak in July 2006.
The number of ultra-high-net-worth households, which Spectrem defines as those with $5 million or more in investable assets, increased 8 percent, to 1.1 million in 2010, the survey said.
Household wealth was $56.8 trillion at the end of 2010, according to the Federal Reserve. Millionaires control about 56 percent of U.S. wealth, according to a March 14 survey by Boston-based Fidelity Investments, the second-largest U.S. mutual-fund company after Vanguard Group Inc.
Millionaires turned bullish on their investments in February for the first time in more than three years, according to a Feb. 23 survey by Spectrem. Walper said he expects optimism may fall slightly in March.
"The whole issue in Japan and with the markets eroding worldwide will increase people's concerns," in the short-term, he said. "But generally, we're still trending upwards."
Millionaires said they're most likely to invest more in stocks in 2011, with holding cash coming in second, Spectrem said.
Ultra-high-net-worth households said their greatest personal concern is the financial situation of their children or grandchildren. Mass affluent households, by contrast, which Spectrem defines as those with $100,000 to $999,999 in assets, said maintaining their current financial position was their greatest concern, followed by having enough money for retirement.
Spectrem's report is based on four sets of surveys of more than 6,000 households conducted online throughout 2010.