Photo: Erica Fischer. Source (Openverse). License: CC BY 2.0.
The September 11, 2026 CPI release is scheduled for 8:30 a.m. Eastern Time, but traders should not assume every related Kalshi contract remains open until that moment. A September 4 source check found different cutoff language for the monthly CPI event, including an unresolved 8:25 versus 8:29 distinction.
By Kalshi View Editorial Team
Primary sources I checked: the BLS September 2026 release calendar, the BLS CPI release schedule, and the official Kalshi API records for KXCPI-26AUG and KXCPIYOY-26AUG. The source snapshot was taken September 4, 2026, seven calendar days before the scheduled release.
The Bureau of Labor Statistics schedules the Consumer Price Index for August 2026 for Friday, September 11, 2026, at 8:30 a.m. Eastern Time. BLS states that all times on its release calendar are Eastern Time.
This is August data released in September. It should not be confused with the CPI report covering September 2026, which the CPI-specific BLS schedule lists for October 14, 2026.
The September 11 date is scheduled, not immutable. BLS says its calendars are updated as needed, so traders should recheck the official calendar during release week. The BLS CPI program page is the official destination for the report itself, but it does not define Kalshi trading or settlement rules.
For broader calendar context, see the earlier August 2026 CPI release calendar guide. This page serves as the dated final-week verification layer rather than repeating the full advance calendar.
The central finding in the September 4 snapshot is a source discrepancy affecting KXCPI-26AUG, titled “CPI in August.” The two relevant Kalshi sources do not show the same last-trading time:
This guide does not choose between those sources or claim that one overrides the other. It also does not treat 8:31 as a settlement time. Traders should open the exact market through Kalshi markets, inspect its current rules and timestamps, and resolve any uncertainty before submitting an order.
The year-over-year event was more consistent in the dated evidence. Every nested market in KXCPIYOY-26AUG had an API close time of 2026-09-11T12:29:00Z, which is 8:29 a.m. EDT. Its generic terms PDF also identifies 8:29 a.m. ET as the last trading time and 8:31 a.m. ET as expiration.
The similar names should not obscure the different underlyings:
As of September 4, the exact KXCPI-26AUG response contained 15 nested objects marked active, with thresholds ranging from more than -0.4% through more than 1.0%. KXCPIYOY-26AUG contained 26 active nested objects, with thresholds from more than 2.5% through more than 5.0%.
Those 41 active statuses are a dated API observation, not a promise that every market will remain available. They also say nothing about prices, liquidity, eligibility, or which threshold is likely. Current availability and prices must come directly from Kalshi.
Kalshi operates as a CFTC-designated contract market, settles contracts in USD, and requires identity verification. The CFTC filing page lists Kalshi as “Designated,” but that status does not validate a particular CPI contract, price, interpretation, or outcome. Access can be available internationally subject to the Member Agreement, restricted jurisdictions, identity verification, and local law.
The evergreen Kalshi CPI market mechanics guide covers broader contract setup. Readers seeking additional source links can also follow the @Kalshi_market channel.
BLS schedules the August 2026 Consumer Price Index report for Friday, September 11, 2026, at 8:30 a.m. Eastern Time. The calendar is updated as needed, so this remains a scheduled time rather than a guarantee. Traders should recheck the official BLS calendar before the release.
The report scheduled for September 11 covers the August 2026 reference month. CPI reports are released after the month being measured. BLS separately schedules the report covering September 2026 for October 14, 2026, so the release month and reference month should not be treated as the same thing.
The September 4 snapshot does not provide one consistent answer. The exact KXCPI-26AUG event rules and API close metadata point to 8:25 a.m. ET, while the linked generic KXCPI terms PDF says 8:29 a.m. ET. This guide does not resolve that conflict. Check the exact live market and its current rules directly on Kalshi before acting.
KXCPI-26AUG concerns the one-month, seasonally adjusted CPI-U percent change, rounded to one decimal. KXCPIYOY-26AUG concerns the not-seasonally-adjusted all-items CPI-U change over the twelve months ending August 2026, also represented to one decimal. Their thresholds and cutoff evidence must be checked separately.
Not financial advice. Prediction-market trading is speculative, and you can lose money. Do your own research.