How to read the December decision odds

Read the named row and time

At about 19:06 UTC October 29, 2026, Kalshi’s December page displayed 77% “Hike 25bps” and 23% “Fed maintains rate” in its Chance headings. Polymarket’s December page displayed 77% “25 bps increase” and 22% “No change” in named rows. These are separate event-contract readings. Access time is not a venue quote timestamp.

What they settle on

Both event pages refer to the scheduled December 9 Fed decision, but the venues publish separate contract rules. Read the full “Rules” text on Polymarket and the contract terms on Kalshi before treating their similarly named outcomes as identical. The visible pages do not expose all rule text in this accessible view, so no detailed equivalence claim is made here.

What a row cannot tell you

Kalshi also shows a separate order-entry odds label; this comparison uses its named Chance headings. Do not average the venues, derive a residual from rounded rows, or call a price the Fed’s forecast. Polymarket’s experimental AI narrative is not evidence of why prices moved. The change between two page checks does not reveal the quote-time path or cause. An October decision result does not answer a December policy-path or asset-return question.

Futures are a different measure

CME FedWatch derives probabilities from 30-Day Fed Funds futures, not event-contract trades. Its live December grid and quote time were unreadable here, so no CME percentage or cross-venue spread is shown.