A stock market rally, which has since reversed, propelled U.S. household net worth to a record high of $109 trillion in the July-September quarter.

The Federal Reserve said Thursday that the value of Americans' stock and mutual fund holdings soared $1.2 trillion. Home values rose $200 billion. Other assets, such as bank accounts, also increased. Total net worth climbed $2 trillion from nearly $107 trillion in the April-June quarter.

Greater household wealth can help the economy by lifting consumer spending. Yet wealth has been increasingly concentrated since the Great Recession, with just 10 percent of U.S. population owning 84 percent of stocks.

Richer households are less likely to spend from additional wealth compared with poorer ones.

The figure reflects the value of assets like homes, bank accounts and stocks minus debts like mortgages and credit cards. The figures aren't adjusted for inflation or population growth.

Since the July-September quarter covered by the Fed's report, household wealth has suffered a sharp blow, and may be on track to decline in the final three months of 2018.

The S&P 500 stock market index reached a record high Sept. 20, only to fall steadily through October and November. It has also fallen sharply this week over fears of a worsening trade fight between the United States and China and a potential slowdown in U.S. and global economic growth.

On Thursday, the S&P 500 fell sharply through most of the day before recovering after a news report suggested that the Federal Reserve could slow its current pace of interest rate hikes. The index closed down just 4 points, or 0.2 percent, at 2,696.

The increasing importance of stock ownership to building wealth, compared with owning a home, has exacerbated wealth inequality since the recession. For most middle-class Americans, real estate ownership is the main source of wealth.

While home prices have risen at a robust pace for the past five years, they haven't increased as much as stocks. And home price growth has slowed this year, along with sales.

Strong gains in household wealth haven't spurred as much spending in the past decade as in previous years. Historically, in what economists call the "wealth effect," an additional dollar in financial or real estate wealth has lifted spending by 3 to 5 cents, which accelerates the economy.

But since the recession, Americans have been more reluctant to spend from their wealth. Economists suggest that households increasingly see wealth gains as potentially temporary and are more cautious about spending it as a result.