WASHINGTON — While Wall Street celebrates yet another stock market record — surpassing 20,000 on the Dow Jones industrial average — many Americans have little reason to cheer.

Despite the spread of 401(k) retirement plans, the wealthiest 10 percent of households own roughly 80 percent of stock market wealth. The Dow’s 23 percent surge over the past year has benefited mostly investors who were already well-off.

The rising concentration of wealth at the top is one reason why the economy’s significant gains since the Great Recession ended 7½ years ago haven’t been felt by many Americans. Though the Dow more than doubled in President Barack Obama’s two terms, pay growth was stagnant, especially for people without higher education or high-tech skills. Discontent and anxiety about the economy helped fuel President Donald Trump’s victory.

Now, a major challenge for Trump is to help extend the economy’s gains beyond wealthier households and those in thriving large metro areas to struggling regions and many rural areas.

Research by Edward Wolff, an economist at New York University, found that the wealthiest 10 percent of households owned 81.4 percent of stock market wealth as of 2013, the most recent year for which figures are available. The middle 60 percent of U.S. households owned just 7.7 percent. Those figures include stocks held in individual retirement plans and 401(k)s as well as in mutual funds.

“Any boom in the stock market is going to pass by the great majority of Americans,” Wolff said.

Other data echo his findings. The richest 1 percent of Americans owned 44 percent of stock market wealth in 2012, according to calculations by Gabriel Zucman, an economist at the University of California, Berkeley.

A rising stock market does provide benefits to the broader economy. Wealthier households typically increase their spending as their assets rise in value. Even Americans with only modest retirement accounts may feel wealthier and spend more. Such increased spending can spur economic growth and lead to more hiring.

For typical American families, though, the largest source of wealth is the equity in their home. In large part, that explains why even after the recession ended many Americans enjoyed little improvement in their finances.