July Inflation US - Annual

Platform comparison

Market context

July’s US annual inflation print is the year-over-year change in CPI-U for the 12 months ending in July 2026, with the BLS due to publish the number on 12 August 2026. The market’s 2% YES price is far below the latest realised June reading of 3.5% and implies traders think the annual rate will need to fall sharply in a single month, which generally requires either a notably soft monthly CPI or a strong base-effect from July 2025.[14][15]

Recent comparable prints frame the probability as a low-tail outcome rather than a base case. CPI was 4.2% in May 2026, then dropped to 3.5% in June after a 0.4% monthly fall, the first decline since April 2020, while core inflation eased to 2.6%.[1][4][8][14] Forecasts published around mid-July clustered around 3.8% for June and near 3.3% to 3.9% for July, depending on the model, which is still well above the low-single-digit level implied by the market price for a July-2026 annual reading near 2%.[2][3][5][7][9] On Polymarket, that 2% is a straight implied probability; on Kalshi, the same view is usually expressed through contract pricing rather than percentage odds, while Betfair and Smarkets tend to show decimal prices and charge exchange-style fees, with access and KYC requirements varying by jurisdiction.

The main catalyst is the BLS July CPI release on 12 August 2026 at 8:30 am ET, and traders will be watching the monthly CPI print because it determines how far the annual rate can move from June’s 3.5%.[10][13][15] The prior report showed energy and gasoline were key drivers, with energy up 15.7% over the year and gasoline up 26.7%, so another drop in fuel prices would matter disproportionately for the headline number.[14] For cross-platform comparison, that matters because fee drag is more visible on smaller probabilities: a 2% contract can look similar across books, but net value depends on whether the venue uses order-book pricing, exchange commissions, or a built-in spread.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares July Inflation US - Annual specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Robinhood Prediction Markets, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Robinhood Prediction Markets has a different geo footprint and routes to Polymarket's order book at 0% fees.