CHICAGO — Americans’ wealth rose in the January-March quarter, boosted mainly by the best quarterly gain in stock prices since 1998 and partly by the first rise in home values since 2006.

Household net worth rose 4.7 percent to $62.9 trillion last quarter, according to a Federal Reserve report released Thursday. The main reason was a 12 percent jump in the Standard & Poor’s 500 index, which padded the portfolios of Americans who own stocks.

Home values increased 2.3 percent.

But since March ended, the progress Americans have made to recover the wealth they lost in the Great Recession has hit another bump. Stocks sank 6 percent in May amid rising fears about Europe’s debt crisis and a weakening U.S. economy. And there’s scant evidence of a sustained housing market recovery despite the uptick in home values.

Household wealth, or net worth, reflects the value of assets like homes, bank accounts and stocks, minus debts like mortgages and credit cards. It bottomed during the recession at roughly $49 trillion in the first quarter of 2009. It’s still about 5 percent below its pre-recession peak of $66 trillion.

Americans’ borrowing rose at an annual rate of 5.8 percent. It was the first time consumers have boosted their borrowing by at least 5 percent in two straight quarters since mid-2008, just before the financial crisis.

Household debt, which has been declining for four years, dipped 0.4 percent last quarter. Americans have been steadily shrinking their debt loads.

Home mortgage debt, which has been declining since 2008, fell an additional 2.9 percent. But the drop can be deceiving. Mortgage debt is falling mainly because many Americans have defaulted on payments and lost homes to foreclosure — not just because people are paying off loans.

The overall gain in Americans’ net worth was driven by the biggest quarterly rise in the S&P 500 in 14 years. But the stock index has since shed about half that increase.

The surge in stocks didn’t help as many Americans as it would have in the past. The percentage of U.S. households that own individual stocks or stock mutual funds declined to 46 percent last year, down from 59 percent in 2001, according to the Investment Company Institute.

For most American households, home equity, not stocks, represents their main source of wealth.

“It’s a mixed outlook for the typical household,” says Scott Hoyt, senior director of consumer economics at Moody’s Analytics.

Consumers are more affected, Hoyt said, by other factors: a job market that’s improving only fitfully, declining gasoline prices and generally stagnant home values.

Though the S&P 500 remains 15 percent below its October 2007 peak, employees who have stayed invested in 401(k) plans and continued to contribute have benefited. About 94 percent of them now have more money in those accounts than before the market top 4½ years ago, according to the Employee Benefit Research Institute in Washington.