Stocks Slip as Inflation Story Gets More Complicated

Investors flinched on Tuesday after the release of government data that upended the trend of falling inflation and signaled that the Federal Reserve’s campaign to rein in rising prices is far from complete.

After a day of choppy trading, as investors digested the data, the S&P 500 ended up roughly in line with where it had begun. U.S. government bond yields rose, reflecting expectations for higher interest rates as the Fed tries to bring inflation back under control.

Investors had taken solace in recent months from a consistent slowing in inflation, helping to push the benchmark U.S. stock index up more than 6 percent in January. The prospect of a continued drop in the pace of price increases has recently lifted hopes that the Fed will soon stop raising interest rates, which have helped reduce inflation but have also raised costs for consumers and companies by making it more expensive to get a mortgage or take out business loans, for example.

Such exuberance had come under pressure in recent weeks, with the S&P 500 inching just 1.4 percent higher this month, ahead of the latest release of the Consumer Price Index on Tuesday. The data for January showed price increases accelerating on a monthly basis, although the year-over-year numbers continued to show a slight easing.

“This idea that we can get continued disinflation without a material slowdown in the economy has been the narrative the market has run with,” said Priya Misra, an interest rate strategist at TD Securities. “But that has come under pressure, and today reinforced it.”

Already, a robust jobs market, rising used-car prices and upward revisions to past inflation numbers had complicated the picture for investors.

At the same time, policymakers have reignited expectations that the Fed will continue raising interest rates until the middle of the year, pushing up U.S. government bond yields and weighing on stock prices.

The yield on the two-year Treasury bond nudged above 4.6 percent on Tuesday, its highest level of the year. The yield, which is sensitive to changes in Fed policy, had already risen roughly 0.25 percentage points this month ahead of the numbers — equal to the size of a typical rate increase from the central bank.

And the persistent weakening of the U.S. dollar, when compared with a basket of currencies representing its major trading partners, had paused. On Tuesday, the dollar rallied back from earlier losses after the fresh inflation data came out but still ended the day 0.1 percent lower.

Bond investors had already begun to recalibrate their expectations for the number of interest rate increases to come from the Fed.

At the start of February, futures markets, which allow investors to bet on the path of interest rates, suggested a consensus view that the Fed would make just one more quarter-point rate increase when it met in March. That has since risen to decent odds that there will be three increases of that size through July, which would take the Fed’s target rate to a range of 5.25 to 5.5 percent, above the Fed’s own forecasts published in December.

It is a stark turnaround from the market’s skepticism of the Fed’s forecasts as recently as just a few weeks ago.

“If you ask 10 people what they think inflation will do, you will get 12 opinions with cogent arguments back,” said Jim Sarni, a managing director at the asset manager Payden & Rygel. He maintains that inflation may have peaked even if the pace of its moderation slows and there are occasional monthly “blips.”

Such mixed signals in the market this year reflect the uncertain outlook noted by Mr. Sarni. Inflation is falling and the economy remains robust, raising hopes among investors that a severe downturn will be avoided. Yet inflation remains high, and corners of the economy are proving resilient to the Fed’s actions, raising the risk that the central bank will have to do even more to slow the economy — a point reiterated by some Fed policymakers in public comments on Tuesday.

“Last year, we had too much pessimism, but right now, we have a market that has got ahead of itself and is a little too optimistic,” Mr. Sarni said. “Markets are vulnerable in the short run for that reason.”