WASHINGTON — Millions of Americans suffered a loss of wealth during the recession and the sluggish recovery that followed. But the last half-decade has proved far worse for black and Hispanic families than for white families, starkly widening the already large gulf in wealth between non-Hispanic white Americans and most minority groups, according to a new study from the Urban Institute.

“It was already dismal,” Darrick Hamilton, a professor at the New School in New York, said of the wealth gap between black and white households. “It got even worse.”

Given the dynamics of the housing recovery and the rebound in the stock market, the wealth gap might still be growing, experts said, further dimming the prospects for economic advancement for current and future generations of Americans from minority groups.

The Urban Institute study found that the racial wealth gap yawned during the recession, even as the income gap between white Americans and nonwhite Americans remained stable. As of 2010, white families, on average, earned about $2 for every $1 that black and Hispanic families earned, a ratio that has remained roughly constant for the last 30 years. But when it comes to wealth — as measured by assets, like cash savings, homes and retirement accounts, minus debts, like mortgages and credit card balances — white families have far outpaced black and Hispanic ones. Before the recession, non-Hispanic white families, on average, were about four times as wealthy as nonwhite families, according to the Urban Institute’s analysis of Federal Reserve data. By 2010, whites were about six times as wealthy.