Jobs Gains Surge, Troubling News for the Federal Reserve.

Federal Reserve officials are likely to cast a wary eye on September jobs data, which showed that employers both hired at a rapid clip last month and had added more workers in the previous two months than had been reported earlier.

Employers added 336,000 jobs last month, sharply more than the 170,000 economists had predicted. Fed officials have been keeping a careful watch on the labor market as they try to assess how much more they need to raise interest rates to bring inflation under control, and how long borrowing costs should stay high.

Central bankers had been encouraged as job growth had cooled without collapsing in recent months. They have continued to predict that unemployment will probably rise slightly as the economy slows: To about 4.1 percent, which would still be low by historical standards. Unemployment stood at 3.8 percent as of September.

“Although the jobs-to-workers gap has narrowed, labor demand still exceeds the supply of available workers,” Jerome H. Powell, the Fed chair, said during a news conference in mid-September. Fed officials “expect the rebalancing in the labor market to continue, easing upward pressures on inflation.”

Friday’s report offered little evidence that hiring was continuing to cool, though — instead suggesting that companies continued to snap up workers. That made Wall Street investors wary that the Fed might raise interest rates further, something that would weigh on corporate profits and stock valuations.

Central bankers have already lifted rates to 5.25 to 5.5 percent, and have suggested that they could make one more rate move in 2023 before holding borrowing costs at a high level in 2024.

S&P 500 quickly slipped 0.8 percent, and the 10-year Treasury yield, which is a crucial benchmark interest rate around the world, rose to 4.8 percent after the report.

Joe Rennison contributed reporting.