Prediction Markets: What UK Betting Players Should Know

What are prediction markets?

Prediction markets let people trade on the outcome of a future event, such as an election, a sports result or an economic number. Each market offers contracts that pay a fixed amount, often 1 dollar or 100 pence, if the event happens and nothing if it doesn't. The price of a contract moves between 0 and 100 as people buy and sell, and that price is read as the crowd's estimate of the probability.

If a contract for "yes" costs 30p, the market is saying roughly a 30% chance. Buy it and the event happens, and you collect 100p. If it doesn't, you lose your 30p. You can usually sell before the event if the price moves your way.

Who sets the price of a contract?

Nobody sets it directly. The price is wherever the last buyer and seller agreed to trade. When news breaks, traders who think the event's chances have improved buy and push the price up; traders who disagree sell. Some platforms add a market maker to keep prices quoted. The price is a crowd estimate, not a guarantee, and a contract trading at 90 still loses one time in ten if that estimate is right.

How is a prediction market different from a bookmaker?

A bookmaker sets the odds and takes the other side of your bet. Its margin is built into those odds. A prediction market matches you with other traders instead, and the platform earns from fees or the spread between buying and selling prices. In that sense it works like a betting exchange, where people back and lay outcomes against each other.

How is it different from a casino game?

A casino game has a fixed mathematical house edge: roulette, blackjack and slots all keep a set share of stakes over time. A prediction market has no house edge in that sense. Your result depends on whether your view of the event beats other traders' views, minus fees. That doesn't make it safer. Most traders lose, prices can move fast, and markets on obscure events can be thin, so you may not be able to sell when you want to.

Are prediction markets legal in the UK?

In Great Britain, a bet on the outcome of an event is gambling, and anyone offering it to British customers needs a licence from the UK Gambling Commission. Betting exchanges such as Betfair Exchange and Smarkets hold that licence, which is why they can offer event markets here.

As of October 2026, the best-known prediction market platforms, Polymarket and Kalshi, don't hold Gambling Commission licences and aren't available to users in Great Britain. Their event contracts are treated as bets in the UK rather than as financial products, so they can't rely on financial-services rules to operate here. Reports in 2026 describe talks with the Financial Conduct Authority about how such products might be regulated, so this may change. Until it does, a site offering event contracts to British users without a Gambling Commission licence is unlicensed.

You can check any operator on the Gambling Commission public register.

What are the risks of offshore prediction markets?

• No UK protection. An unlicensed platform doesn't have to verify your age, offer deposit limits or self-exclusion, or use an approved dispute service.
• Crypto exposure. Many platforms settle in stablecoins, so you also carry wallet, exchange and transfer risk.
• Using a VPN to reach a platform that blocks your country usually breaks its terms, and it can mean your account and balance are frozen.
• Thin markets. Small markets can be moved by a few large traders, and you may not find a buyer when you want out.

Can I use prediction markets for sports?

Sports event contracts look like bets because they're bets. In the UK, the licensed way to back or lay a sports result is a UKGC-licensed bookmaker or betting exchange. Exchanges charge commission on net winnings instead of building a margin into the odds, so compare commission rates the way you'd compare rake at a poker room. Our sportsbooks section explains how we rate betting sites, and every licensed operator must offer the responsible gambling tools described in our guide.

Do we list prediction markets?

No. BestCasinoPortal covers casinos and licensed betting sites, and we don't list or link to prediction market platforms. If you want the closest licensed equivalent, compare betting exchanges that hold a Gambling Commission licence, read their commission terms, and set a budget before you trade. For casino games, our list of UK casino sites shows licensed brands rated on our Trust Index.

We'd treat any advert for an event-contract app aimed at UK users with suspicion until the platform appears on the Gambling Commission register. Check the register first; it takes a minute.

Key takeaways

• Prediction markets trade contracts priced as probabilities between 0 and 100.
• They match you with other traders, like a betting exchange, and charge fees.
• In Great Britain they count as betting and need a Gambling Commission licence.
• In October 2026 Polymarket and Kalshi aren't licensed for, or available to, British users.
• Licensed exchanges are the lawful way to trade event outcomes in the UK.
• Offshore platforms come without the UK safeguards: no reliable age checks, no deposit limits, no approved dispute service.
• Check the Gambling Commission register before you trade on any event platform.

18+. Gamble responsibly. If betting or trading on events stops being fun, GamCare offers free, confidential support, and the National Gambling Helpline is on 0808 8020 133.