September CPI monthly: Polymarket Puts 0.6% at 54% Before BLS

The September CPI monthly print lands Wednesday, and Polymarket has a favorite. In our snapshot at 06:03 UTC (09:03 MSK) on October 13, the 0.6% bucket led "September Inflation US - Monthly" at 54% Yes, with 0.5% at 33% and 0.7% at 13%. The BLS releases the data on October 14 at 8:30 a.m. ET, which is 15:30 MSK.

What actually happened

The September Inflation US - Monthly market resolves on the one-month percent change in seasonally adjusted CPI-U for September 2026, as published by the Bureau of Labor Statistics. BLS reports it to one decimal place, so 0.55% rounds to a clean bucket on the release.

At 06:03 UTC, traders put 54% on 0.6%, 33% on 0.5% and 13% on 0.7%. Every other bucket was under 4%. When we pulled event data a few minutes later, total volume was about $73.1K, so this is a mid-sized macro book, not a whale pool.

August set the base. Headline CPI rose 0.4% on the month, per both previews, and annual inflation ran at 3.4%. The question is how big the September jump gets.

The forecast spread

investingLive says the market expects headline CPI up 0.6% in September, citing Westpac's calendar, which would lift the annual rate to about 3.7% from 3.4%. It notes the Cleveland Fed nowcast points to about 0.5% for the month and 3.6% on the year.

Morningstar cites FactSet for a 0.5% monthly gain and 3.6% year over year. We're not averaging the two. The Polymarket board basically mirrors this split, with 0.6% favored and 0.5% the strong runner-up.

One housekeeping note. Morningstar's highlights list the release as "Wednesday, Oct. 15." October 15 is a Thursday this year. The BLS schedule cited in Polymarket's rules says Wednesday, October 14, at 8:30 a.m. ET, and investingLive agrees, so that is the date we use.

Energy up, core calm

investingLive expects energy prices to rise around 5.5% in September, the largest energy contribution since March, with gasoline in the lead. Brent above $100 is the backdrop. Food is seen subdued.

Core is the calmer story. Both previews expect about 0.2% on the month and 2.4% annually. investingLive says August's 0.3% core was boosted by a one-off jump in telephone services after a methodology change. Bank of America economists, quoted by Morningstar, warn of upside risk and a possible second straight 0.3%.

For the core side of this trade, see our September core CPI odds piece. This article is about headline only.

What Polymarket thinks

On the September CPI monthly market, the 0.6% bucket traded at 54% Yes in our 06:03 UTC snapshot. Add 0.5% at 33% and 0.7% at 13%, and traders saw almost the whole outcome sitting in three adjacent buckets.

That tight cluster tells you the debate is about one tenth of a percentage point, not about direction. Everyone expects a hot headline. The fight is how hot.

A 0.1 point miss can flip this market and barely move the Fed. Core can move the Fed and barely touch this market.

How it connects to crypto

Crypto traders care because hot inflation keeps rate-hike talk alive. BeInCrypto, writing about Tuesday's overnight liquidations, flagged the CPI release as the next test for leveraged bulls. A hotter print could strengthen rate-hike bets and add selling pressure, while softer inflation could ease them.

What to do as a reader

Set the time in your own zone. The release is Wednesday at 8:30 ET, which is 15:30 MSK. The market resolves on the official release, so expect it to settle within minutes if BLS publishes on schedule.

Watch the right number. This market is headline CPI-U, seasonally adjusted, month over month. Year-over-year and core figures are different markets and different headlines.

Think about the Fed link. A hot core reading is what could revive October hike bets, as our October rate hike odds coverage explains. If you quote the September CPI monthly odds, keep the timestamp: 54% on 0.6% at 09:03 MSK. Nothing here is investment advice.