WASHINGTON (MarketWatch) — The U.S. economy looks much more vigorous in the second quarter than previously thought, as a report released Thursday showed businesses got off the sidelines and spent some money.

The acceleration in business investment, if it’s sustained, could add to the economy’s momentum in the months ahead. The data show why the Federal Reserve is considering hiking interest rates at its next meeting in September.

The U.S. economy grew at a faster 3.7% annual pace in the second quarter, up from the initial estimate of growth at a 2.3% clip, the Commerce Department said Thursday.

Economists polled by MarketWatch forecast gross domestic product would be revised up to 3.3%, but business investment was stronger than expected. The government estimated last month that gross domestic product expanded at a seasonally adjusted 2.3% clip from April to June.

U.S. stocks, which have gyrated over the concerns about China’s economy, climbed on Thursday.

Consumer spending, the main driver of U.S. economic activity, led the way as usual. Outlays were revised up to 3.1% from 2.9% in the second quarter after a tepid 1.8% gain in the first three months of the year.

What’s more, newly revised figures from the Commerce Department show that businesses invested at an even faster rate.

Businesses increased investment by 3.2% increase of a drop of 0.6%, with spending on structures such as office buildings rising by 3.1% instead of a drop of 1.6%.

One reason businesses might have invested more: Corporate profits jumped an estimated 2.4% in the second quarter after declining by 5.8% in the first quarter.

And they boosted spending on equipment by 10.7%, rather than 7%..

It’s not clear this pace can be sustained. For instance, state and local government spending was boosted to 4.3% from 2.0%, the fastest pace since 2001. Economists don’t think this will last.

And the value of inventories, which adds to GDP, increased by $121.1 billion in the second quarter instead of a previously estimated $110.0 billion. This is expected to subtract from growth in the third and fourth quarter.

But real final sales to private domestic purchasers, a measure of activity without inventories, saw a stronger upward gain than many economists expected, from 2.5% to 3.3%.

Economists polled by MarketWatch forecast the U.S. will grow at a 2.8% pace in the July-September quarter. But that was before this week’s financial market volatility.

Inflation as measured by the PCE price index rose at a 2.2% annual rate.

William Dudley, the president of the New York Fed, said Wednesday that recent economic data has been pretty positive. He indicated that he had been at least very close to backing a rate hike at the Fed’s Sept. 16-17 meeting.

However, recent financial market turmoil has complicated the U.S. central bank’s plans. Dudley told reporters the steep market declines had made a rate increase “less compelling.”

Read more:Dudley backs away from September rate hike

It may be months before economists will know whether this week’s stock sell-off is an economically important shock.

“The key to the monetary policy stance in the near term will not be past growth or inflation performance, but the outlook for both,” said Millan Mulraine, deputy chief economist at TD Securities.

“And given the recent financial market volatility and the lingering anxiety about global growth, the outlook for both is now more uncertain and tilted to the downside, especially for inflation. This will provide the pretext for the Fed to take a pass on raising rates in September,” he added.