What is Polymarket's typical spread?

Measured across 5,143 markets in the last 7 days, Polymarket's median two-sided spread was 3.37%. Lower is better for bettors.

How often does Polymarket have the best odds?

Where at least five tracked books priced the same market, Polymarket posted the single best price 17.1% of the time over the last 7 days.

How is Polymarket's spread measured?

Omenizer records every price on every tracked market, converts them to implied probabilities, and sums each market's sides; the amount over 100% is the bookmaker's margin. The figure here is the median across all of the book's observed markets — measured, not quoted from marketing material.

Tracked bookmakers · prediction market

Polymarket: margins and market data

Prediction market. Prices on Polymarket are set by traders on an order book, not by a bookmaker. The figure below is the typical two-sided spread across its markets — measured exactly as we measure a bookmaker's margin, but it means something different: nobody set it as a fee, and Polymarket's own charges (where it has any) are billed separately rather than built into the price. It is reported here, and deliberately not ranked against sportsbooks.

Across 5,143 markets observed in the last 7 days (6 sports, 39 leagues), Polymarket's median spread was 3.37%. Where at least five books priced the same market, Polymarket had the single best price 17.1% of the time.

Market family	Median margin
Moneyline / match result	3.90%
Handicaps / spreads	3.90%
Totals	0.00%

Price only — fees not verified. The figure above is what Polymarket's prices imply, before any commission or fee it charges. Omenizer has not verified Polymarket's fee schedule, so it cannot be compared like-for-like with a venue whose costs we know, and it is left out of our cost comparison for the same reason. A low price with unknown fees is not the same as a low total cost.

Polymarket spread by sport

Only sports with 50+ observed Polymarket markets in the last 7 days are shown — a median over less is noise.

Sport	Median margin	Best price	Markets (7d)
Baseball	3.66%	12.8%	2,080
Soccer	0.00%	21.4%	1,265
Tennis	4.10%	23.3%	1,259
Basketball	0.00%	4.3%	269
American Football	3.88%	6.8%	175
Fighting	3.43%	10.9%	95

Who runs Polymarket

Availability: licensed in AU, CA, NO, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US, US. (reported — verification in progress)

What others say about Polymarket

Independent scores published elsewhere, each linked to the page it was read from and dated. Omenizer does not collect or host reviews — these are other people's numbers, reproduced so you can check them.

Source	Score	Reviews	Checked
Apple App Store (US)	4.6 / 5	52,781	source 2026-08-15
Google Play (US)	3.6 / 5	9,243	source 2026-08-15

In the last 90 days, Polymarket posted the board-leading price on 160 signals flagged by Omenizer's detection engine.

On an order book, the spread is what it costs to cross it: the gap between the best price to buy and the best price to sell. A 3.37% spread means the two sides of a typical Polymarket market together imply about 103.37% — the cost of trading in and straight back out. It is set by whoever is quoting at that moment, not by Polymarket, and it moves with liquidity.

FAQ

What is Polymarket's typical spread?: Measured across 5,143 markets in the last 7 days, Polymarket's median two-sided spread was 3.37%. Lower is better for bettors.
How often does Polymarket have the best odds?: Where at least five tracked books priced the same market, Polymarket posted the single best price 17.1% of the time over the last 7 days.
How is Polymarket's spread measured?: Omenizer records every price on every tracked market, converts them to implied probabilities, and sums each market's sides; the amount over 100% is the bookmaker's margin. The figure here is the median across all of the book's observed markets — measured, not quoted from marketing material.

See where Polymarket beats fair value — free account

Live reference — data refreshes daily · the dataset · all tracked bookmakers

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