The best prediction market for you depends mostly on where you live: in the United States, CFTC-regulated exchanges such as Kalshi, Polymarket US and the venues behind brokers like Robinhood; outside the US and its close-only list, Polymarket's international platform has the most depth on world events; in the UK, licensed betting exchanges such as Betfair and Smarkets list similar political markets. This comparison was checked on 8 November 2026. Disclosure: Nimb maps Polymarket and earns a builder fee on orders routed through it; there are no affiliate links on this page.
Which prediction markets are there?
| Venue | Type | Money | Where | Best for |
|---|---|---|---|---|
| Polymarket (international) | Crypto order book | pUSD on Polygon | Worldwide except the US, UK, France, about 35 other close-only countries and sanctioned places | Depth on world events, free public data |
| Polymarket US | CFTC-regulated exchange | US dollars | Most US states | US users who want Polymarket markets |
| Kalshi | CFTC-regulated exchange | US dollars (crypto deposits converted) | US, and many other countries since 2025 | Economics, rates, weather, sport, US politics |
| Robinhood prediction markets | Broker access to regulated exchanges | US dollars | US | Existing Robinhood users; compared |
| Interactive Brokers ForecastEx | CFTC-regulated exchange | US dollars | US and some other countries | Economic and climate questions in a broker account |
| PredictIt | US political market | US dollars | US | US politics, small stakes |
| Betfair Exchange, Smarkets | Licensed betting exchanges | Pounds, euros | UK and some other countries | UK users; politics and sport |
| Crypto-native venues (e.g. Opinion, Limitless, Myriad) | On-chain markets | Stablecoins | Varies | Niche and short-term crypto markets; compared |
| Manifold, Metaculus | Play money or reputation | None | Worldwide | Practice and forecasting without money |
Products, country lists and limits change often. Check each venue's own terms before you sign up.
How do you choose a prediction market?
- Is it legal for you? Location first. Do not use a VPN to get round a block. Are prediction markets legal?
- Depth on what you care about. A market with a 1-point spread and millions traded is a better price than one with a 10-point spread. Spread and depth.
- All-in cost. Fee formula plus spread, at the prices you trade. Fees.
- Custody. A regulated account held by the venue, or a self-custody wallet you are responsible for.
- Resolution. Who decides the outcome, and how disputes work. How markets resolve.
- Data. Can you see the order book, history and holders? Polymarket's are public; others publish less.
Best prediction markets for beginners
The simplest start is not to trade at all: read the prices. Nimb, Polymarket and Kalshi all show markets without an account. If you trade, start with a regulated venue available where you live, a small amount you can lose, and a market with a narrow spread. On Polymarket through Nimb, the ticket shows the payout, the break-even and every fee before you sign. Get started · Risks.
Best prediction markets outside the US, in the UK and in Europe
- Outside the US, Polymarket's international platform has the deepest markets on world events where it is allowed, and Kalshi has opened to many countries. Polymarket vs Kalshi.
- In the UK, Polymarket is close-only. Licensed betting exchanges (Betfair Exchange, Smarkets) offer political and sports markets under Gambling Commission licences; check Kalshi's country list for the UK.
- In Europe, it varies by country: Polymarket is close-only in France, Germany, Italy, Belgium, Poland and others, and open in several. Full list.
Frequently asked questions
What is the biggest prediction market?
Polymarket and Kalshi are the two largest by volume in 2026; which leads depends on the month and how volume is counted. Statistics.
What is the best legal prediction market in the US?
CFTC-regulated exchanges: Kalshi, Polymarket US and others, directly or through brokers. Some states contest sports contracts.
Are there free prediction markets?
Play-money platforms such as Manifold, and forecasting sites such as Metaculus, cost nothing. Reading real-money prices on Nimb is also free.
Which prediction market is the most accurate?
Accuracy depends on the market's depth and the question more than the venue. Are prediction markets accurate?
Last reviewed 8 November 2026 · Data from Polymarket · Not financial advice · Nimb is not affiliated with Polymarket.