A betting exchange, also called a bet exchange, is a marketplace where bettors bet against each other and not against a sportsbook. One customer backs a result, another takes the opposite side at the same price, and the exchange charges the winner a commission.
The exchange sets no prices of its own. Customers post the odds they want, and a bet exists only once somebody accepts it. This page uses decimal odds, where 2.50 is the same price as +150.
Backing and laying, with one bet
To back is to bet that something happens, as you would at a sportsbook. To lay is to bet that it does not: you play the bookmaker for one customer’s bet, take their stake if they lose and pay them if they win.
Take a $100 bet on Team A at 2.50. The price implies a 40% chance (1 / 2.50), and the two sides of the bet look like this.
| Backer | Layer | |
|---|---|---|
| Puts at risk | $100 | $150 |
| Team A wins | +$150 | -$150 |
| Team A does not win | -$100 | +$100 |
The layer’s $150 is called the liability: the stake multiplied by the decimal price minus 1. A lay at a long price risks far more than it can win, so check that number before you offer one.
Laying also lets you close a bet early. Say you backed Team A for $100 at 2.50 and the price shortens to 2.00. Lay $125 at 2.00 (the $250 return divided by the new price) and you are $25 ahead whether Team A wins or not, before commission. Our hedging guide covers the same move with two sportsbook bets.
Commission against the sportsbook’s margin
A sportsbook is paid through its prices. On an even game it posts -110 on both sides: each side implies 52.38%, the two add up to 104.76%, and a winning $100 bet makes $90.91. Our guide to how betting odds work shows that conversion.
An exchange is paid after the result. Betfair’s charges page, read on October 13, 2026, says commission is charged on a customer’s net winnings in a market, that a net loss in a market pays no commission, and that the amount is the net winnings multiplied by the market’s base rate. Its worked examples use rates of 2% and 5%. On Betfair the rate depends on the market and on the account.
Put the same even game on an exchange at 2.00 and the difference is easy to count.
| Where the $100 bet wins | Winner keeps | Win rate to break even |
|---|---|---|
| Sportsbook at -110 | $90.91 | 52.38% |
| Exchange at 2.00, 5% commission | $95.00 | 51.28% |
| Exchange at 2.00, 2% commission | $98.00 | 50.51% |
At 5%, the exchange bet is the same as a price of about -105. On the $100 bet at 2.50 from the first table, a 5% commission takes $7.50 of the backer’s $150, or $5 of the layer’s $100, and nothing from whoever loses.
That comparison holds only if the exchange has a 2.00 to take. The price to back sits at or below the price to lay, and in a thin market that gap can cost more than the commission saves.
How a betting exchange differs from a sportsbook
| Betting exchange | Sportsbook | |
|---|---|---|
| Who sets the price | Customers, by posting offers | The sportsbook |
| Who you bet against | Another customer | The sportsbook |
| What it costs | Commission on net winnings | A margin inside the prices, 4.76% at -110 on both sides |
| What caps your bet | The money other customers have offered at that price | The book’s maximum, which it can set per customer |
| Betting against a result | Yes, by laying | Only by backing the other side |
Start with the cap. FanDuel’s house rules for Massachusetts, dated July 30, 2026, put the maximum bet at $5,000,000 and let the book set a different maximum for any customer, so the cap at a sportsbook is the book’s decision. On an exchange the cap is the amount on offer.
That amount is called liquidity. Betfair’s exchange rules separate matched bets from unmatched ones, meaning bets a customer has asked for that have not been accepted yet. A $500 offer with $80 taken is an $80 bet, and the other $420 waits or is cancelled. The size of an offer matters as much as its price.
Betting exchanges in the United States
Availability in the United States is limited. As of October 13, 2026, we could not confirm, from a state regulator’s list together with the operator’s own site, an exchange open for sports bets under a state sports betting licence. No operator is named here for that reason.
Check your state regulator’s list of approved operators before you send money to any site that calls itself an exchange. The arithmetic above stays the same wherever one is open: a 40% price is still 2.50, and a 5% commission still turns $150 into $142.50. For the prices sportsbooks post today, our moneyline guide is the place to start.