Fed’s preferred gauge showed core inflation at 3.0% in August, much lighter than expected

Consumer prices posted a smaller-than-expected increase in August from a year ago, according to the Federal Reserve's primary inflation gauge, the Commerce Department reported Wednesday.

The personal consumption expenditures price index rose a seasonally adjusted 0.3% for the month, putting the 12-month gain at 3.4%. Economists surveyed by Dow Jones had been looking for increases of 0.3% and 3.7%, respectively.

Excluding food and energy, PCE posted a 0.2% climb that put the annual core level at 3%. The respective forecasts were for 0.3% and 3.3%.

Though the Fed officially follows the headline PCE number, officials generally consider core a better gauge of longer-term trends.

While the annual increases were less than expected, they came as the Bureau of Economic Analysis changed the way it computes several components of the index. The BEA adjusted methodology for how it measures prices for legal services, software and computer accessories and portfolio management.

Stock market futures gained ground following the report while Treasury yields were negative. Traders priced in less of a chance of a Fed rate hike in October, pushing the next expected increase to December.

"This is good news for investors worried about the recent surge in bond yields, and it bolsters the case for not hiking in October," said David Russell, global head of market strategy at TradeStation. "However, it's also relatively old data at this point that doesn't reflect this month's surge in diesel prices."

The report also showed that personal income rose 0.2% while spending increased 0.9%, against the respective consensus for 0.4% and 0.8%.

Both PCE levels are still considerably higher than the central bank's 2% target, raising the possibility that the Fed will follow up its September interest rate hike with another increase at either of its remaining meetings this year — in October or, more likely, December.

"Even after major methodological revisions, PCE inflation is still running hot however you cut it," said Sonu Varghese, global macro strategist at Carson Group. "The economy is running hot, policy remains easy, and the Fed's challenge is figuring out how much restraint is needed. That's a tailwind for stocks as we move into Q4."

Energy costs were the primary culprit for the price rise in August, though multiple other sectors also showed gains. Gasoline jumped 4.4% and transportation services accelerated by 1.4%. Energy goods and services climbed 2.3%.

"The PCE Inflation data – the Federal Reserve's favorite – show no progress in August on inflation," said Heather Long, chief economist at Navy Federal Credit Union. "And it's inevitable that September will be higher. Meanwhile, American consumers are feeling the squeeze."