WASHINGTON — Fueled by higher stock and home values, Americans’ net worth reached a record high in the final three months of 2014.

Household wealth rose 1.9 percent during the October-December quarter to nearly $83 trillion, the Federal Reserve said Thursday. Stock and mutual fund portfolios gained $742 billion, while the value of Americans’ homes rose $356 billion.

The typical household didn’t benefit much, though. Most of the wealth remains concentrated among richer families. The wealthiest 10 percent of U.S. households own about 80 percent of stocks.

Still, greater wealth could help lift spending and economic growth. Higher stock and home values can make people feel more financially secure and more willing to spend, and consumer spending fuels about 70 percent of the economy.

The Fed’s figures aren’t adjusted for population growth or inflation. Household wealth, or net worth, reflects the value of homes, stocks and other assets minus mortgages, credit cards and other debts

U.S. corporations are also seeing sharp improvements in their finances, the Fed report showed. Businesses amassed $2 trillion in cash by the end of last year– a record high – up from less than $1.9 trillion three months earlier.

Cash-rich corporations could spend more on investments in machinery, computers and other equipment. That would make workers more productive and accelerate economic growth.

They could also use some of their cash to raise pay at a time when many employees have been stuck with stagnant wages. Some economists have criticized publicly traded companies for spending heavily on repurchasing their own shares, which boosts profits and serves shareholders rather than employees.

Businesses are also taking advantage of low interest rates by taking on more debt.