August 2026 CPI Release

BLS released July CPI this morning and every chain printed a tick above its modal outcome. Headline YoY came in at 3.4% against a book centered on 3.3%. Headline MoM printed 0.1% against a chain that put 60.5% above 0.0% and only 15.5% above 0.1%. Core YoY landed at 2.5% against a 2.4% center, and core MoM at 0.2% against 0.1%. Four chains, four one-tick upside misses in the same direction.

The workspace has rolled to the August print, due Wednesday, September 11. Kalshi lists it as the same full cumulative chain—headline MoM, headline YoY, core YoY, core MoM—structurally a strike chain on inflation. Read it the way you would an options chain and you can see where the market thinks inflation lands and how wide the tails are.

Where the August chains sit today. Headline YoY crosses 50% right at 3.4% (66.5% above 3.3%, 49% above 3.4%)—the market expects this morning's number to hold rather than fade. Headline MoM crosses at 0.2% (72% above 0.1%, 47% above 0.2%), a step up from July. Core YoY centers at 2.4% (87.5% above 2.3%, 37.5% above 2.4%), a step back down. Core YoY is the deepest book on the page at $16.2k in 24-hour volume, with headline YoY at $5.8k and headline MoM at $4.1k.

Kalshi's cumulative August CPI event displayed as its native chart, paired with headline YoY. A month out from the release these chains are wide—the YoY distribution runs from 3.1% at 97% down to 3.6% at 7%, against a July book that had compressed inside a 0.4-point band by T-24h. Watch the 50% crossing on each: that strike is the market's point estimate, and it will tighten through early September.

The Categorical books sit next to the core chains. The cumulative-versus-Categorical gap this workspace flagged yesterday resolved in the Categorical's favor: the chain priced at-or-above 0.1% MoM at 15.5% while the Categorical priced exactly 0.1% at 39.5%, and 0.1% is what printed. On YoY the chain had above-3.4% at 17.5% against the Categorical's 36.5% at exactly 3.4%—3.4% printed. For August the same structure is live again: the Categorical puts exactly 3.4% at 42.5% against a chain crossing right there.

The sharper disagreement now is cross-exchange. Manifold prices August headline MoM at or above 0.3% at 70%; the Kalshi chain prices the same threshold at 47%. That is a 23-point gap on one number. Below: Polymarket's full-year 2026 inflation market and a Manifold sanity check on annual inflation above 3%.

• Four chains, four upside misses. July headline YoY, headline MoM, core YoY and core MoM each printed exactly one tick above where the cumulative chain centered. A single miss is noise; four in the same direction on one release is a systematic tilt worth pricing into September.
• The Categorical beat the chain twice. Same exchange, same underlying number, two presentations—and the bucket book was closer on both headline measures. This is the cleanest worked example of chain-versus-bucket pricing the platform has produced, and it now has a scored outcome attached.
• August prices the July level holding. Headline YoY crosses at 3.4%, exactly where July landed. Headline MoM crosses at 0.2%, up a tick. Core YoY crosses at 2.4%, down a tick from July's 2.5%. The market's base case is a flat headline with core easing underneath it.
• Manifold and Kalshi disagree by 23 points. At-or-above 0.3% MoM: 70% on Manifold, 47% on Kalshi. Manifold's book is thin ($512/24h) against Kalshi's chain, so the likeliest explanation is liquidity rather than information—but it is the widest cross-exchange gap in this series.
• Headline still runs above core. Kalshi prices core above headline in August at just 3.5%. The 0.9-point wedge is energy and food, and the gas price tracker—where the pump ladder just moved up to $4.07—is the live input.
• The September 11 print lands four days before the FOMC. Read this chain against the FOMC tracker; a second consecutive upside surprise puts the September hike back in play.
• A month out, treat rung moves as drift. Volume is $16.2k on core YoY and thinner elsewhere. These chains do not become informative until the week of the release.