Polymarket’s named hike row is 53%; Kalshi’s named hike row is 52%.
The FOMC statement is the authority for the completed September decision. The rows below are direct October event-contract observations accessed at 19:05 UTC on September 22, not a pooled forecast.
| Measure | What the pool can report | Method and limit |
|---|---|---|
| FOMC statement | Raised the target range by 25 bp to 3.75%–4.00% in a 12–0 vote. | Official September result, released 14:00 EDT. It is not a market measure or an October forecast. |
| Kalshi: Fed decision in October? | 52% for “Hike 25bps”; 48% for “Fed maintains rate”; Cut 25bps below 1%. | Direct event-series headings at pool access. Since 13:38 UTC: each named row +1 point; two outcomes are hidden. |
| Polymarket: Fed Decision in October? | 53% for a 25 bp increase; 46% for no change. | Direct multi-outcome event contract. Since 13:38 UTC: named hike +3 points; no change −4. Rules use the upper-bound target-range change and name the October FOMC statement as resolution source. |
| CME FedWatch | Current October figure not directly captured. | CME describes the tool as probabilities implied by 30-Day Fed Funds futures. Its live grid was unreadable, so no third-party number is used for a spread. |
Different instruments do not create a pooled probability
Kalshi’s 4-point named hike lead and Polymarket’s 7-point named hike lead are readings on separate pages. They do not form a complete distribution, prove a shared probability, or create an expected return.
A numerical gap is not an arbitrage finding
Before comparing any percentages, match the named instrument, exact outcome, rule or calculation, observation time, and access or trading conditions. A futures-implied figure and an event-contract row may answer related but distinct questions. This pool does not assess fees, execution, eligibility, liquidity or tradability.
Keep the scope aligned
An October-decision row does not answer whether the Fed will raise at least once more by year-end or explain an asset move. Those questions need their own clearly named contract, calculation, or evidence.
Federal Reserve October calendar · CME methodology · Read the contract guide