US Inflation Accelerates to 3.7% in September, Fueling Fed Rate Hike Expectations

US consumer prices accelerated in September, with the annual inflation rate climbing to 3.7%, further cementing concerns that the cost of living remains stubbornly elevated. The Bureau of Labor Statistics reported Wednesday that the Consumer Price Index (CPI), a broad measure of goods and services costs, rose by a seasonally adjusted 0.6% for the month, matching economists' expectations. However, the annual rate exceeded the Dow Jones consensus forecast of 3.6%.

Stripping out the volatile categories of food and energy, the so-called core CPI also showed an uptick, rising 0.3% monthly. This figure was slightly above the 0.2% estimate. Annually, core inflation stood at 2.6%, exceeding the 2.5% forecast. These numbers indicate that inflationary pressures are not solely confined to energy, though that sector remains a significant factor.

Inflationary Pressures Broaden

The energy index saw a substantial jump of 5.2% in September, primarily due to continued tensions between the U.S. and Iran following a conflict that began in late February. Gasoline prices alone soared 9.1% for the month, accounting for approximately half of the overall headline CPI increase. Over the past year, gasoline has climbed 34.2%, while fuel oil has surged an even more dramatic 74.2%.

Beyond energy, other components also contributed to the persistent price increases. Shelter costs advanced 0.4% for the month, while used car and truck prices rose by 0.7%. Apparel prices, which are often sensitive to tariffs, increased 0.3% and are up 3.4% over the last year. Food prices, however, remained flat in September, though they are 2.5% higher than a year ago.

Market reactions were swift, with stock market futures turning negative and bond yields rising sharply following the data release. Traders also adjusted their expectations for Federal Reserve policy. According to the CME Group's FedWatch tool, the probability of a rate hike at the Federal Open Market Committee's (FOMC) upcoming meeting on October 27-28 increased to about 54%, while odds for a rate increase before the end of the year surged to over 96%, with a near 50-50 chance of a half-percentage-point increase by December.

Sonu Varghese, chief macro strategist at Carson Group, noted that the September CPI reading came in "hot" and was not solely driven by fuel prices, with core inflation running at an annualized pace of 3.7% for the month. Varghese highlighted that investors continue to be surprised by broad-based inflation, suggesting that the full impact of higher diesel prices and the artificial intelligence boom has yet to be seen.

Why it matters

This latest CPI report is the final inflation data that FOMC officials will review before their crucial meeting later this month. The Federal Reserve has maintained its target inflation rate at 2% since March 2021, a benchmark that the CPI has consistently surpassed. While inflation had shown signs of moderating earlier in 2026, it spiked again following strikes launched by the U.S. and Israel against Iran.

Policymakers typically view supply shocks, such as those driving the current energy surge, as temporary and often look past them when setting interest rates. However, Fed officials are increasingly concerned that the prolonged conflict and its impact could embed higher prices into the broader economy and influence consumer and business expectations. This risk could necessitate further monetary tightening to prevent inflation from becoming entrenched.

The Fed initiated its first interest rate hike in over three years in September, raising the benchmark funds rate by a quarter percentage point to a target range of 3.75%-4%. While markets had previously anticipated the Fed might skip an October increase, the latest inflation data complicates this outlook. Beyond energy, prices also face pressure from President Donald Trump's tariffs and robust demand for goods related to the artificial intelligence build-out.

What to watch

While some key policymakers have recently suggested the Fed does not need to rush another rate hike, most still expect at least one more increase this year. Market pricing currently implies the Fed could raise rates at least twice more in 2027. The Bureau of Labor Statistics will release the September Producer Price Index (PPI), a measure of wholesale costs, on Thursday, offering further insight into pipeline inflation pressures.

Investors will also closely monitor the Commerce Department's personal consumption expenditures (PCE) price index for September, which the Fed uses as its primary inflation metric for forecasting and policymaking. The PCE numbers are scheduled for release later this month and will provide another critical data point for the central bank's deliberations.