The rich are certainly getting richer.

More Americans are reaching millionaire status, according to a new study, with the number of wealthy households nationwide returning to pre-recession levels thanks in part to the stock market’s strong performance last year.

The number of wealthy households in the country has continued to increase over the past four years, according to investor research firm Spectrem Group and creator of the Annual Market Insights Report for 2014. The report finds wealth segments across the board saw major increases from 2012 to 2013.

The number of millionaires in the country reached a record 8.39 million last year, an increase of 440,000 since 2012 and 2.53 million more since the 2008 financial crisis. During that time, there were only 5.86 million millionaires in the U.S.

Spectrem reports that Mass Affluent Households, with net-worth’s between $100,000 and $1 million, grew to 28.97 million nationwide. The wealth number does not include primary residence and is an increase of 500,000 investors since 2012 and 2.77 million over the post-recession lows of 25.2 million.

The Ultra-High Net Worth segment, which includes those with $5-$25 million in net worth, hit 1.108 million in 2013, up 85,000 from the year earlier. And, an increase of 352,000 since 2008.

The wealthiest Americans, with $25 million in net worth or more, increased by 15,000 individuals from 2012, up nearly 10%. Spectrem reports that in 2008, there were only 84,000 investors with a net worth of $25 million or higher.

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