Prediction-market odds of a Federal Reserve interest rate hike in October surged on October 14 after the September consumer price report showed U.S. inflation running hotter than expected. On Polymarket, the probability of a 25-basis-point increase climbed roughly 25 percentage points during Wednesday's trading to 43%, while the probability of unchanged rates held at 57% ahead of the October 27–28 policy meeting.

The catalyst was an inflation print that exceeded forecasts by just 0.1 percentage point. Annual U.S. CPI inflation reached 3.7% in September, above the 3.6% forecast and August's 3.4% reading. That comparison became a focal point for markets assessing whether progress on inflation had stalled before the Federal Reserve's next interest rate decision. The figures captured a rapid shift in expectations, though they stopped short of making another increase the favored outcome.

BREAKING: Market expectations for an October rate hike surge to 43% after US CPI inflation hits its third highest level since September 2023. October rate hike expectations are up +25 percentage points today. Another highly uncertain Fed decision is ahead. pic.twitter.com/NJi0k1ICiK — The Kobeissi Letter (@KobeissiLetter) October 14, 2026

The September reading marked the third-highest annual CPI level since September 2023, according to The Kobeissi Letter. The report also showed core inflation running above forecasts, placing attention on price pressures beyond gasoline. The distinction matters, as energy-driven increases and broader inflation carry separate implications for the central bank's 2% inflation objective.

September CPI Hits 3.7% as Core Inflation Exceeds Forecasts

Headline prices increased 0.6% in September, accelerating from August's 0.4% monthly gain. Gasoline costs jumped 9.1% and accounted for more than half of the increase, while the broader energy index climbed 5.2%, explaining much of the immediate pressure on household budgets. Other categories contributed as well, leaving a report dominated by, but not defined by, energy.

The increase extended into other spending categories. Shelter prices rose 0.4%, alongside higher prices for used vehicles, airline fares, medical care, and apparel. Those movements showed that inflation was not confined to fuel, an important distinction when interpreting the core inflation figures.

Core consumer prices, which exclude food and energy, advanced 0.3% on the month, above the expected 0.2%. Annual core inflation reached 2.6%, compared with forecasts of 2.5% and August's 2.4%. Both annual inflation readings remained above the central bank's target.

CME Hike Odds Reach 43.7% Ahead of PPI and October Meeting

The Federal Reserve had already increased its benchmark rate by 25 basis points, to 3.75%–4.00%, on September 16. Meeting minutes showed most policymakers considered another increase appropriate before year-end, while keeping decisions dependent on incoming economic data. That data-dependent framing is why a single consumer price release was enough to move October hike odds by more than 20 percentage points across both prediction markets and futures pricing.

The repricing was visible beyond Polymarket. CME FedWatch put the likelihood of an October increase at 43.7%, up from 22.1% before the inflation release, a 21.6-percentage-point rise in expectations. Two-year Treasury yields climbed, the dollar strengthened, and U.S. equities declined as financial markets reacted to the report.

Higher borrowing costs also affect liquidity conditions surrounding Bitcoin and Ethereum, which is why digital-asset market participants track the Fed's rate path alongside traditional markets even when a macro report contains no crypto price data. The inflation report provided no cryptocurrency price figures.

Attention now turns to September's Producer Price Index, scheduled for October 15. September Personal Consumption Expenditures data, the central bank's preferred inflation gauge, are set to follow on October 29, one day after the October 27–28 policy meeting concludes. The two releases will give the committee updated inflation readings as it weighs whether to deliver another increase before year-end. For now, unchanged rates remain the leading outcome for October.

Source: Blockonomi