CPI Comes in Hot Enough to Put a Fed Rate Hike Firmly on the Table

The August Consumer Price Index delivered a mixed inflation message Friday morning, but not one likely to make the Federal Reserve comfortable. Headline inflation came in exactly as economists expected, while core CPI was slightly hotter than forecast. The immediate reaction was dramatic: fed funds futures pushed the probability of a 25-basis-point rate hike at next week's Federal Reserve meeting to roughly 88%, up from 67% immediately before the report.

The Bureau of Labor Statistics reported that headline CPI increased 0.4% month over month, matching the consensus estimate and accelerating sharply from July's 0.1% increase. On a year-over-year basis, inflation held at 3.4%, also matching expectations.

The surprise came underneath the surface. Core CPI, excluding food and energy, increased 0.3% month over month versus the 0.2% consensus, although the year-over-year rate eased to 2.4% from 2.5%, matching expectations.

That 2.4% core reading was the lowest since April 2021, providing an important positive within an otherwise uncomfortable report. Inflation is clearly well below its cycle highs. The problem for the Fed is that the monthly data suggest the final stage of disinflation remains difficult, while renewed energy inflation threatens to reverse some of that progress.

Sticky Services Remain the Concern

Perhaps the most important detail wasn't headline or even conventional core CPI. It was the behavior of supercore inflation, generally defined as core services excluding housing.

Supercore prices increased approximately 0.5% in August, an outsized monthly increase and a reminder that underlying service inflation remains sticky.

Housing itself wasn't responsible for the hotter core reading. The shelter index increased 0.3%, but owners' equivalent rent increased only 0.2%, while primary rent also rose just 0.2%. That is encouraging because housing carries enormous weight in CPI and has been one of the most persistent sources of post-pandemic inflation.

Instead, pressure appeared elsewhere in services.

Lodging away from home jumped 2.4%, airline fares increased 2.7%, communication prices rose 2.3% and education increased 0.8%. Those increases were partly offset by a 0.2% decline in medical care and a 0.8% drop in motor-vehicle insurance.

The distinction matters for the Fed. A continued cooling in rent and OER suggests the long-awaited shelter disinflation remains intact, but a 0.5% supercore increase makes it difficult to declare victory over sticky services.

Goods inflation was comparatively contained, although used cars and trucks increased 0.4% and new vehicles rose 0.3%.

Energy Is Becoming a Bigger Problem

Energy was responsible for much of the acceleration in headline CPI.

The energy index increased 2.1% in August after falling 1.5% in July, while gasoline jumped 3.9% and accounted for more than one-third of the entire monthly increase in CPI. Over the past year, energy prices are up a striking 16.3%, led by a 27.4% increase in gasoline.

That follows Thursday's PPI report, where energy was also the dominant inflationary force.

There may finally be some relief developing Friday. Oil prices are pulling back modestly following reports that the Gulf Cooperation Council will meet with Iran, raising hopes that diplomacy could reduce some of the geopolitical risk premium embedded in crude.

That's constructive for future inflation readings, but it doesn't erase the inflation already flowing through the economy. Energy prices remained elevated through much of the period measured by August CPI, and the recent Middle East shock could continue affecting transportation, airfare and other downstream prices.

Food was considerably better behaved. Food prices increased just 0.1%, while food at home was unchanged. Food away from home increased 0.3%.

Fed Hike Odds Surge to 88%

The market's monetary-policy response leaves little ambiguity about how investors interpreted the report.

Before CPI, fed funds futures assigned approximately a 67% probability to a rate hike next week. Following the release, those odds surged to approximately 88%.

That makes a hike the market's overwhelming base case.

The Fed's dilemma isn't that inflation is spiraling out of control. It is that inflation remains too elevated and too sticky for policymakers to comfortably maintain the current policy stance without risking their inflation-fighting credibility.

Core CPI at 2.4% is the lowest since April 2021, shelter inflation continues to improve and some individual categories are clearly cooling. Those are meaningful positives.

But headline inflation remains 3.4%, energy inflation is running at 16.3% year over year, supercore services jumped 0.5% in August, and monthly core CPI came in hotter than economists expected.

With next week's FOMC meeting approaching, the hurdle for another hike appears to have fallen substantially.

The Treasury Market Is Sending an Interesting Signal

Perhaps the most fascinating reaction came from bonds.

The 10-year Treasury yield was trading around 4.98% immediately ahead of CPI, dangerously close to the psychologically important 5% threshold. Yet following a slightly hotter-than-expected core inflation report, the yield fell roughly four basis points.

Ordinarily, hotter inflation and an increase in Fed tightening expectations should push yields higher.

Instead, the long end rallied even as the probability of a Fed hike jumped.

That could be an early indication that the Treasury market would actually welcome tighter Fed policy.

Long-term Treasury yields incorporate more than expectations for the overnight federal funds rate. Investors also demand compensation for future inflation and uncertainty about monetary-policy credibility. If bond investors become concerned that the Fed is falling behind inflation, long-term yields can rise even without a change in the policy rate.

A hike next week could therefore create an unusual dynamic: short-term rates rise while longer-term Treasury yields decline, producing a flatter yield curve.

The message would be straightforward—the bond market believes tighter policy today reduces the risk of more persistent inflation tomorrow.

That interpretation is particularly notable after Treasury Secretary Scott Bessent's $6 billion long-duration Treasury buyback failed to prevent yields from rising, while Thursday's broadly in-line PPI report still pushed the 10-year as high as roughly 4.91%. The European Central Bank also raised rates by 25 basis points this week as policymakers there confront renewed inflation pressure.

Inflation Is Better, But Not Yet Good Enough

There are legitimate positives in Friday's CPI report.

Core inflation falling to 2.4%—its lowest level since April 2021—is significant. OER and rent increasing just 0.2% suggests shelter inflation continues to normalize. Food inflation was subdued, medical costs declined and insurance prices fell.

But those improvements coexist with a 0.3% monthly core reading, 0.5% supercore inflation and a major resurgence in energy costs.

That's why the market's reaction may be more important than any single CPI component.

Fed hike odds surged from 67% to 88%, yet the 10-year yield fell from near 5%.

If that relationship holds, investors may be telling the Fed that they don't fear another 25-basis-point hike nearly as much as they fear a central bank that allows inflation to remain elevated.

The Fed has spent years rebuilding its inflation-fighting credentials. With inflation still above target and sticky services refusing to disappear, next week's decision could determine whether the bond market believes those credentials remain intact.

August CPI wasn't disastrously hot—but it may have been just hot enough to make another Fed rate hike necessary.