How Sports Prediction Markets Work
A sports prediction market is a venue where traders buy and sell contracts on the outcome of a match. Each contract settles at 1 if the outcome happens and 0 if it does not, so a contract trading at 0.62 carries an implied probability of 62%. Prices come from an order book. Traders post the prices they will buy and sell at, and the venue matches them. Nobody hands you a price to accept or decline. The venue earns a fee on matched volume instead of taking the other side of your position.
That last sentence is the whole structural difference, and it is worth more than the label on the front door.
Where the term came from
"Prediction market" is an American import. It attached itself to a group of US venues offering contracts on elections, economic data and, more recently, sport.
The machinery underneath is older than the term. In February 2026 the Gambling Commission's Director of Strategy, Brad Enright, set out the regulator's view: these products would fall under the Betting Intermediary definition in UK legislation, because their core aspects are "akin to what in the UK would be described as a 'Betting Exchange.'" He also noted that exchanges have operated in Britain since 2000.
So the regulator and the technology agree. What matters is not what a venue calls itself. It is who sits on the other side of your trade, how the price gets made, what you pay, and how long you wait for your money.
How the order book sets the price
An order book is a live list of every unmatched order on a market, sorted by price.
You want to buy Arsenal to win at 0.55. Someone else will sell at 0.55. The book matches you and both positions open at that price. If nobody will sell at 0.55, your order rests in the book until someone takes it, or until you cancel.
Price moves because orders move. A red card, a substitution, a goal, a team sheet leak an hour before kick-off: each of those changes what traders will pay, the book reprices, and the new number reflects the balance of money on each side. No trading desk pushes the number. On Pred, matching runs in 200 milliseconds, which is what makes in-play trading viable at all.
What a price of 0.62 means
A contract price is a probability with a currency sign in front of it.
At 0.62, you pay 62c to hold a contract that pays 1.00 if the outcome lands and nothing if it does not. Risk 62c to make 38c. The market is telling you it thinks the outcome is 62% likely.
Sell side works the same way in reverse. Selling at 0.62 means you collect 62c now and owe 1.00 if the outcome lands, so you are risking 38c to make 62c. Buying "no" and selling "yes" are the same trade.
The two sides always sum to 1.00. Buy at 0.62 and you have paid what the seller at 0.38 has paid, from the opposite direction.
Who is on the other side of your trade
Another trader. That is the answer, and it has consequences.
A sportsbook is the counterparty to every position it accepts. When you win, it pays from its own book, which means your profitability is a cost line on its P&L. That is the mechanical reason sportsbooks restrict stakes and close accounts, and it is why the practice exists at every operator running that model.
An exchange makes its money on matched volume. Whether you win or lose changes nothing about what the venue earns. A trader who wins consistently posts more volume than one who busts, which makes them worth more to the venue, not less. Pred cannot restrict a winning trader without breaking its own revenue model, so it does not have the mechanism to do it in the first place.
This is also the honest answer to "is this gambling". Arguing about the word is a dead end. Point at the counterparty instead.
What you pay to trade
Two roles, two prices.
A maker posts an order into the book and waits. Makers supply the liquidity that everyone else trades against, so venues charge them less, sometimes nothing, and occasionally pay them a rebate.
A taker hits an order already sitting in the book. Takers consume liquidity, so they pay the higher rate.
Fees are charged on matched contracts. An order that never fills costs nothing. Both Kalshi and Polymarket publish schedules built on the same shape, where the fee scales with the contract price and peaks around 0.50, because that is where the venue carries most risk.
You also pay the spread, which is the gap between the best buy and the best sell. On a liquid Premier League match line that gap is small. On an obscure market at 3am it will not be. The spread is a real cost and it is separate from the fee.
Compare that to a bookmaker's margin, which is priced into the number you see rather than charged on top. Researchers at University College Dublin measured it across 84,230 professional football matches in 22 leagues over eleven seasons. The average position lost 7.8% of stake to margin, higher than the 6.5% a standard overround calculation predicts, because bookmakers price a wider margin into longshots.
How a market settles, and how long it takes
Settlement is where the money moves, and it is the least examined part of the category.
Once the outcome is known, winning contracts pay 1.00 and losing contracts expire at zero. Getting from "the match ended" to "the balance updated" is where venues differ enormously.
Polymarket resolves through the UMA optimistic oracle. Someone proposes the outcome with a bond behind it, and Polymarket's own documentation describes a two-hour challenge window before an unchallenged proposal is accepted. A disputed market escalates to a token holder vote and takes four to six days.
Pred settles from the confirmed result in under three to four minutes. A full-time whistle at 16:52 means funds are available before five o'clock, in USDC, on Base.
For an election market resolving over a fortnight, two hours is a rounding error. For a Saturday afternoon where you want the same capital working in the 17:30 kick-off, it is the difference between trading the next match and watching it.
What makes sports different
Most explainers of this category use elections and weather as their examples. Sport behaves differently in four ways.
Liquidity concentrates. Volume builds through the week and spikes in the hour before kick-off. Trading a Tuesday night Championship match on Sunday means accepting a wider spread than trading it at 19:30 on the night.
Prices move in seconds, not days. A goal in the 88th minute reprices a market faster than any human can react. Matching speed stops being a specification and starts being the product.
Settlement is fast and frequent. A political market resolves once. A Premier League weekend resolves ten times in two days, and capital that sits in unsettled positions is capital not working.
An alternative already exists. Nobody offers you fixed odds on next quarter's inflation print. Every football market on an exchange has a sportsbook version of the same market a tab away, with the margin built into the price. That comparison is available on every single market, which sets a much harder bar than the rest of the category has to clear.
Prediction market, exchange or sportsbook
| Sportsbook | Prediction market | Sports prediction exchange (Pred) | |
|---|---|---|---|
| Counterparty | The operator | Other traders | Other traders |
| Price set by | Trading desk | Order book | Order book |
| What you pay | Margin priced into the odds | Fee on matched contracts, plus spread | Fee on matched contracts, plus spread |
| Winning accounts | Stake limits and closures are standard | No structural reason to restrict | Cannot restrict, by design |
| Typical settlement | Minutes to hours | Two hours or more, longer if disputed | Under three to four minutes |
| Sports depth | Deep | Thin, mostly headline markets | Top European leagues, MLS, NBA, EFL |
Common questions
Are prediction markets the same as betting exchanges? Structurally, close to identical. Both match traders against each other on an order book and charge a fee on matched volume. The Gambling Commission reached the same conclusion in February 2026, placing prediction market products under the Betting Intermediary definition on the basis that their core mechanics match a betting exchange.
Do I need cryptocurrency to trade on Pred? No. Pred accepts fiat deposits as well as crypto. Settlement runs in USDC on Base, but you do not need to hold either to open an account or place your first trade.
Can I lose more than I put in? No. Every contract is fully collateralised between 0 and 1. Your maximum loss on any position is what you paid for it, and the platform holds the funds to cover the other side.
What happens if my order never fills? Nothing. You pay fees on matched contracts only. Resting orders that expire or get cancelled cost you nothing.
Why does the price keep changing before kick-off? Team news, injuries, weather and money. Each new piece of information moves what traders will pay, and the order book reprices in real time. The price you see is the last price two traders agreed on.
Can Pred close my account for winning? No. Pred earns a fee on matched volume and never takes the other side of a trade, so a profitable trader generates more revenue rather than less. The mechanism a sportsbook uses to restrict winners does not exist here.