Polymarket vs a Sportsbook: What Really Changes

Who you are betting against

With a sportsbook (or bookmaker), you bet against the house: it sets the odds and pays you if you win. On Polymarket, there is no house: you buy shares from other players, at the price they agree to sell at. Polymarket earns nothing from the outcome of a game; the platform makes its money from fees on some markets.

The direct consequence: nobody sets the price for you. It moves continuously as people buy and sell, like a stock price.

Price vs odds

A sportsbook shows odds (2.10 in decimal odds, for example); Polymarket shows a price between $0 and $1 (0.47, for example), which reads as a probability: 47%. One converts into the other: decimal odds = 1 ÷ price. A price of 0.47 is equivalent to decimal odds of 2.13 (about +113 in American odds), before fees.

The full calculation, fees included, is in our guide to Polymarket odds.

Who keeps what: the margin

A sportsbook builds its margin into its odds. In France, for example, the law even caps what it pays back: a sports betting operator's return-to-player rate cannot exceed 85% of stakes over the year (decree of November 4, 2020). Across all its bets, a sportsbook licensed in France therefore keeps at least 15% of the amounts staked.

On Polymarket, there is no house margin, but there are two costs:

• fees on some markets, paid by whoever takes an order already in the book: zero on many markets, about 2.5% for a sports share bought at 0.50 (details in our fees guide);
• the spread between the best buy price and the best sell price: small on big markets, wider on small ones.

Don't jump to conclusions, though: without a house margin, it is still a zero-sum game between players. What you win, someone else loses, and many of the players on the other side are professionals or bots. Lower costs don't make bets any easier to win.

What you can bet on

In France, a licensed operator offers bets on sports (and on horse racing, for operators licensed for it), from a list of competitions and bet types set by the ANJ, the French gambling regulator. Polymarket offers sports, but also politics, the economy, geopolitics, culture or the weather. These non-sports bets are not allowed in France. In other countries, what sportsbooks may offer depends on local rules.

Getting out before the end

On Polymarket, you can sell your shares at any time, at the market price. If your team is 2-0 up at half-time, a share bought at 0.45 may be worth 0.85, and you can cash out without waiting for the final whistle. Sportsbooks sometimes offer a "cash out", but they are the ones who set the amount.

Deposits, results and transparency

• Money: a sportsbook works in your local currency (card, bank transfer). Polymarket works in digital dollars (USDC) on the Polygon blockchain: you have to go through a crypto platform to deposit (see how to deposit).
• Results: at a sportsbook, the operator settles bets according to its own rules. On Polymarket, each market's outcome is proposed and then validated by an oracle (UMA), with a dispute period, according to rules written in advance on the market page.
• Transparency: on Polymarket, every bet is public on the blockchain. That is what makes copy trading possible.

Player protection and legality

This is the most important point, and it depends on where you live:

• In France, operators licensed by the ANJ are legal and subject to its rules: identity checks, deposit limits, self-exclusion, and a mediator in case of dispute.
• Polymarket is not licensed in France. The ANJ ordered it to be blocked on July 16, 2026, and Polymarket is challenging that decision in court.
• Elsewhere, the situation varies from country to country: Polymarket's international platform is also restricted in the United States, the United Kingdom, Australia and Singapore, among others. Check the rules where you live.

So, which one should you choose?

It all depends on what you are looking for and where you live. In France, only operators licensed by the ANJ are allowed. Polymarket offers prices set by the market, often lower costs, non-sports markets and the option to sell at any time, but without the protection of a licensed operator, and it is banned or restricted in several countries.