Fed: Why Polymarket and FedWatch Do Not Measure the Same Thing

Two numbers, two different constructions

The percentages associated with the Fed's next decision circulate quickly in Bitcoin commentary. Yet a quote displayed on Polymarket and a probability calculated by CME FedWatch are not two versions of the same official statistic. They come from different markets, with their own contracts and methods. To understand a shift in expectations, one must first identify the instrument being observed. Without this clarification, a seemingly precise figure can give a misleading picture of what operators actually anticipate.

Polymarket offers shares tied to an outcome defined by the rules of an event. Their price is set by participants' orders. Its help center explains that the displayed probability normally corresponds to the midpoint of the spread between buy and sell offers; when that spread exceeds ten cents, the interface uses the last traded price. The display can therefore differ from the price at which a new transaction would be executed immediately. It reflects a particular market, at a given moment, and not a direct measure of monetary‑policy makers' intentions.

FedWatch starts from rate contracts

CME FedWatch uses the prices of federal‑funds futures contracts to estimate probabilities of rate levels after FOMC meetings. The methodology includes assumptions, notably moves in increments of twenty‑five basis points and a relationship between the effective rate and the target range. This calculation turns price information into monetary‑policy scenarios. It does not result from a poll of Fed members nor from a confidence about their next vote.

Comparing the two tools also requires checking the question being asked. A hike at a specific meeting, a hike before a deadline, and a rate level at year‑end are not identical events. Even a close wording can hide a difference in the resolution criteria. The time of consultation, the time zone, market depth and order flow further complicate any alignment. Two distant percentages therefore do not necessarily prove that one tool is wrong; they may simply be answering different questions.

A conditional indication, not a Bitcoin trajectory

Older data demand the same discipline. A reading from October 16 should not be presented as a current probability on October 19. In the absence of a timestamped observation that allows one to reconstruct exactly the contract and its quote, reusing an old percentage would give an unjustified precision. This is especially true when several providers are combined in a single table without distinguishing their methods. A documented comparison must retain the platform name, the event concerned and the date of each observation, even when the figure appears widely reproduced elsewhere.

For Bitcoin, these probabilities are just one contextual element among many. They can change before the decision and then be revised when new statistics appear. The Fed reminds that its choices are based on a set of economic information and are announced by the FOMC. Even a decision that matches the most‑quoted scenario can be followed by varied market moves. None of these tools calculates a probability of a Bitcoin rise, and none guarantees the consequences of a monetary‑policy decision on its price.