These markets have become a valuable source of information on heavily followed events, where their liquidity rivals the bookmakers'.
From probability to odds
A contract at €0.62 is equivalent to odds of 1.61
Prediction markets have a structural advantage: the prices of an event's outcomes sum to close to 100%, with no built-in margin. The cost is taken elsewhere — platform fees, the bid-ask spread, the cost of exiting early.
Using prediction markets as a reference
On high-visibility events — elections, finals, major tournaments — Polymarket's liquidity is enough to make it a serious estimate, sometimes quicker than traditional bookmakers on non-sport news.
On a Ligue 2 match or an ATP 250 tournament, however, the market is empty or held up by a handful of orders: the price then carries no information. Only use them as a reference where the volume is real.
Mind the legal framework: in France, offering sports betting is reserved to ANJ-licensed operators. Prediction market platforms do not hold that licence, and using them from France is your own responsibility.
Frequently asked questions
Can Polymarket be used as an odds reference?
On very liquid events, yes. Stats&Bet follows these markets alongside French licensed operators, which makes it immediately visible when a prediction price and a bookmaker's odds diverge.
Does the price include fees?
The conversion ignores platform fees and the spread between the best bid and ask. On an illiquid market that spread can be several probability points — far more than a good bookmaker's margin.
Can you arbitrage between a prediction market and a bookmaker?
It is theoretically possible when prices diverge, but deposit and withdrawal delays, fees and legal-status questions in France rarely make it practical for an individual.