How accurate is Polymarket?

By the Cent Signals editorial desk. Last updated June 2026.

TL;DR

Polymarket is broadly accurate as a probability source: across its resolved markets, when prices say an outcome has a 70 percent chance it happens close to 70 percent of the time, and accuracy climbs in high-volume markets near resolution. It is noisier in thin or far-off markets, where one large order can move the price. Cent Signals is a free, independent desk that tracks Polymarket activity and explains how prediction markets price probability, not trading advice.

What “accurate” means for a prediction market

A Polymarket price is not a yes-or-no prediction; it is an implied probability. So accuracy is not measured by asking whether the market “got it right” on a single question. It is measured by calibration: across many markets, do the outcomes priced at 20 cents happen about 20 percent of the time, and the ones priced at 80 cents about 80 percent of the time? A well calibrated source is supposed to be wrong on individual long shots often, by design. For the underlying idea that a price in cents reads as a percentage, see how to read implied probability on Polymarket.

The Brier score, and how Polymarket scores on it

The standard yardstick is the Brier score, the average squared error between a forecast and what actually happened. A perfect forecaster scores 0, a perfectly wrong one scores 1, and a strategy of always guessing 50/50 scores 0.25. Lower is better. Polymarket's own published accuracy page reports an aggregate Brier score in the neighborhood of 0.06 across resolved markets as of 2026, calculated from price snapshots taken one month, one week, one day, twelve hours, and four hours before each market resolved. By the usual reading that is a strong number, comfortably better than typical sports betting lines, which sit closer to 0.18 to 0.22.

Attribute	Polymarket, liquid & near resolution	Polymarket, all resolved markets	Typical sports betting line	Constant 50/50 guess
Brier score (as of 2026)	~0.02 or lower	~0.06	~0.18 to 0.22	0.25
Calibration quality	Near-perfect	Strong	Moderate	None (baseline)
What it reflects	Deep book, news priced in	All resolved markets averaged	Margined betting lines	A constant 50/50 guess

The 0.06 figure is Polymarket's self-published metric across all of its resolved markets; independent studies that focus on thin or early-stage markets report larger errors, which is why the columns above separate liquid, near-resolution markets from the full average.

Liquidity and timing drive most of the accuracy

Accuracy is not evenly distributed. Markets with more than a million dollars in volume score dramatically better in the final hours than thin markets do, because a deep order book absorbs new orders without lurching and prices in news quickly. A lightly traded market can show a number that a single sizeable order would move, so its price carries less information. This is the same reason Cent Signals weights volume and liquidity heavily; see volume vs liquidity on Polymarket for how the two figures change the weight a price deserves. Timing matters too: a market a month out is less settled than the same market a day before it resolves, and deep-tail prices near one cent carry a long-documented favorite-longshot bias.

The 2024 election, and where the critics land

Polymarket's best-known moment was the 2024 US presidential race, where the headline market held a high implied probability for the eventual winner on election night, ahead of the formal call. That is one lopsided, heavily traded market, which is the easiest kind to read correctly. A wider study from Joshua Clinton and TzuFeng Huang at Vanderbilt University looked at about 2,500 political markets and 2.5 billion dollars in volume across Polymarket, Kalshi, and PredictIt in the final five weeks of the campaign. By their measure Polymarket pointed at the eventual winner about 67 percent of the time across all races, below Kalshi at 78 percent and PredictIt at 93 percent, with the gap largest in low-liquidity contests. They also flagged herd-like price movement and noted that minimal position caps let a few large wallets move a thin market. In a separate comparison, professional superforecasters beat Polymarket on a majority of forecast days.

None of that makes the platform inaccurate; it locates the accuracy. The liquid, headline markets are about as reliable as anything available, while the sprawl of small markets is noisier. You can read a live macro example on the market on a 25 basis point Fed cut after the June 2026 meeting, where the price reads as the market's implied chance as of the latest snapshot.

How to read a Polymarket price honestly

A single price is a snapshot of the crowd's implied probability, weighted by the money behind it, not a promise about the future. Read it with three filters: how much volume and liquidity stand behind it, how far the market is from resolution, and how extreme the price is. A deep, near-resolution market sitting at 85 cents is a different kind of figure from a thin market a month out sitting at 3 cents, even though both are probabilities. For how Cent Signals collects and snapshots these numbers, including the caveats, see the methodology page, and browse markets worth a second look for current examples.

Frequently asked questions

How accurate is Polymarket overall?

As a probability source it is well calibrated: across resolved markets, outcomes priced near a given percentage tend to happen at close to that rate, so a basket of 70 percent contracts resolves YES roughly 70 percent of the time. Polymarket's own published metrics put its aggregate Brier score around 0.06 as of 2026, which is strong. Accuracy is highest in heavily traded markets close to resolution and weakest in thin or far-off markets, where a single large order can move the price.

What is a Brier score, and what is Polymarket's?

A Brier score measures the average squared error between a probability forecast and what actually happened. It runs from 0 for a perfect forecaster to 1 for a perfectly wrong one, and a strategy of always guessing 50/50 scores 0.25. Lower is better. Polymarket's published accuracy page reports an aggregate Brier score near 0.06 across resolved markets as of 2026, with markets above one million dollars in volume scoring far lower in the final hours. For comparison, sports betting lines tend to land around 0.18 to 0.22.

Did Polymarket predict the 2024 US election correctly?

The headline presidential market did point at the eventual winner, trading at a high implied probability on election night before the race was formally called. That is a single lopsided market, which is the easiest kind to get right. A Vanderbilt University study of about 2,500 political markets across Polymarket, Kalshi, and PredictIt in the final five weeks found Polymarket pointed at the eventual winner about 67 percent of the time across all races, below Kalshi and PredictIt, with the gap concentrated in lower-liquidity contests.

Are Polymarket markets always accurate?

No. Accuracy is an average across many markets, not a guarantee on any one. A 30 percent contract is meant to be wrong about 30 percent of the time, so individual surprises are expected. Thin markets, markets far from their resolution date, and deep-tail prices near one cent or ninety-nine cents are the least reliable, the last because of a long-documented favorite-longshot bias. Liquidity and time to resolution are the two biggest drivers of how much weight a price deserves.

Is Polymarket more accurate than polls or pundits?

For binary, well-defined questions a liquid market is often at least as accurate as a polling average and tends to update faster as news arrives. It is not strictly better than every alternative: in one head-to-head, professional superforecasters beat Polymarket on a majority of forecast days, and the Vanderbilt study found certain regulated venues edged it on 2024 races. Markets and forecasters each have strengths; Cent Signals reports the market price as one observation, not as a verdict.