The stock market has roared back to record-high territory -- and the number of U.S. millionaires is not far behind, according to a new report.The number of U.S. households worth $1 million or more, excluding the value of their homes, surged to nearly 9 million in 2012.That is just below its pre-recession peak of 9.2 million, according to the Spectrem Group, a Chicago-area financial consultant firm.The recession caused the stock market to tumble by more than half from October 2007 to March 2009, when the Dow Jones industrial average hit a low of 6,443. The fall decimated the nation's ranks of millionaires, which slipped to 6.8 million in 2008 after hitting its peak the previous year, Spectrem said.But the market is back. The Dow closed Thursday at a record high of 14,539, continuing a long surge that has also lifted hundreds of thousands of American families above the millionaire mark.Spectrem's latest count, which the firm arrived at by combining Census Bureau data with information developed by private sources, puts the number of U.S. millionaires at 8.99 million."Just as the stock market crash triggered a steep drop in the net worth of wealthy investors, the rebound in equities has made it possible for many affluent households to largely recover," Spectrem President George Walper said in a statement.The firm said the stock-market rally lifted the number of households with $500,000 or more in net worth to 14.3 million in 2012, up half a million from a year earlier.Meanwhile, the number of what Spectrem calls high-net-worth individuals -- those whose wealth is $5 million to $25 million -- reached 1.14 million at the end of 2012, up from 1.078 million a year earlier.The benefits being reaped by those at the top of the wealth ladder from the booming stock market contrasts sharply to the gains of many Americans.More than 12 million Americans are unemployed, incomes are flat and more than 40 percent of the jobless have been out of work for six months or more.In November, New York University economist Edward Wolff noted that stock ownership is highly concentrated among the affluent.In 2010, the wealthiest 1 percent of Americans owned 35 percent of households' stocks and mutual funds. The next 9 percent held 46 percent of stocks.