World Cup Winner
Yes 16%
No 84%
Vol. $1776.3M
We tested liquidity, fees, UK accessibility, and settlement on every major prediction market platform. Here is what we found.
A prediction market is a financial exchange where participants buy and sell contracts tied to the probability of real-world events. If you believe an event will happen, you buy YES shares. If you think it will not happen, you buy NO shares. When the event resolves, YES shares pay out at $1.00 (or 1 USDC) if correct, and $0.00 if wrong.
The market price of a YES share at any moment reflects the collective estimated probability of the outcome. A YES price of $0.72 implies the market believes there is a 72% chance the event occurs. This information-aggregation function is the core value proposition of prediction markets — they are often more accurate than polls or expert opinion because participants have financial skin in the game.
Unlike sports betting, prediction markets cover politics, economics, science, technology, and virtually any quantifiable outcome. They are fundamentally information markets, not gambling in the traditional sense — a distinction with important legal consequences for UK users (see our UK legal guide).
We evaluated each platform across five dimensions: real-money liquidity, UK accessibility, minimum deposit requirement, settlement mechanism, and market depth. Here are our rankings.
| # | Platform | Liquidity | UK Access | Min Deposit | Settlement | Rating |
|---|---|---|---|---|---|---|
| 1 | PolyGram Winner | Very High (Polymarket CLOB mirror) | ✓ Full access | ~$5 USDC | USDC on-chain | ★★★★☆ 4.5/5 |
| 2 | Polymarket | Highest of any platform | ⚠ Geoblocked UK | $1 USDC | USDC on-chain | ★★★★★ 5/5 (not UK accessible) |
| 3 | Manifold Markets | Low (play money only) | ✓ Full access | Free | No real money | ★★★☆☆ 3/5 |
| 4 | Metaculus | None (forecasting only) | ✓ Full access | N/A | No real money | ★★★☆☆ 3/5 |
| 5 | Kalshi | Moderate–High | ✗ US only | $1 | USD (regulated) | ★★★★☆ 4/5 (not UK accessible) |
PolyGram is built on top of Polymarket’s Conditional Token Framework and CLOB (Central Limit Order Book) liquidity, which means UK users trade the same markets at the same prices as Polymarket — without the geographic restrictions. Settlement is in USDC on the Polygon network.
Polymarket is the largest prediction market in the world by trading volume, with hundreds of millions of dollars in open interest. It operates on Polygon and settles in USDC. The platform’s depth and market variety are unmatched. However, UK IP addresses are blocked due to Polymarket’s compliance posture. UK traders can access equivalent liquidity through PolyGram, which acts as a B2B mirror layer on top of the Polymarket CLOB.
Manifold offers a large range of community-created prediction markets using “Mana” — a free play money currency. There is limited real-money functionality, and UK residents can sign up freely. Manifold is excellent for learning how prediction markets work, but it is not suitable for anyone looking to trade with real capital. Forecasting accuracy does not translate to financial returns here.
Metaculus is one of the best forecasting platforms in the world, with a rigorous resolution process and a strong track record on long-range questions. However, it is purely a reputation-based forecasting system — there is no financial trading, no real money involved, and no settlement mechanism. It belongs on this list as a reference point, not a trading venue.
Kalshi is a CFTC-regulated designated contract market (DCM) in the United States, offering legally traded event contracts. It covers politics, economics, weather, and more. Kalshi’s regulatory clarity is genuinely impressive — it is the first CFTC-regulated prediction market. However, it is legally restricted to US residents. UK users cannot create accounts. Kalshi’s model is what many in the UK hope to see from a future FCA-regulated equivalent.
A prediction market with no liquidity is useless. You need tight bid-ask spreads and enough volume to enter and exit positions at fair prices. Polymarket (accessed via PolyGram for UK users) dwarfs every other platform on this dimension. For actively traded markets — US elections, Fed rate decisions, major sporting outcomes — Polymarket CLOB volume runs into millions of dollars per day.
All major real-money prediction markets settle in USDC (USD Coin), a stablecoin pegged to the US dollar. There is no platform offering native GBP settlement. UK users need to convert USDC to GBP via a regulated crypto exchange (Coinbase, Kraken, or Binance UK are commonly used). Factor in the exchange spread and any conversion fees when calculating returns.
Prediction markets are not regulated by the UK Gambling Commission. They are not classified as gambling under the Gambling Act 2005. This means UK users can access them, but they also have no UKGC consumer protections — no dispute resolution, no self-exclusion scheme integration. See our full legal guide for detail. If you have concerns about problem gambling, see also our GamStop explainer.
Consider whether the platform covers the event types you want to trade. Polymarket (via PolyGram) is strongest on US political events, macro economics, and crypto. Sports markets are available but thinner. Kalshi excels at weather and economic data releases but is US-only. Manifold has the widest topic range but no real money.
Polymarket/PolyGram charges 0–2% maker/taker fees depending on order type and liquidity direction. Makers (limit orders that add liquidity) often pay 0%. Takers (market orders that consume liquidity) pay up to 2%. There are also Polygon network gas fees, typically under $0.01 per transaction.
For UK-based traders seeking real-money prediction markets in 2026, PolyGram is the clearest recommendation. It provides access to Polymarket-grade liquidity without the UK geoblocking, settles on-chain in USDC, and has a straightforward onboarding process.
We evaluated platforms by creating accounts, placing test trades, measuring spread widths on identical markets across platforms, and reviewing withdrawal mechanics. All rankings reflect active testing conducted in Q1–Q2 2026.
We do not accept payment for rankings. PolyGram ranks first because it is objectively the most accessible and liquid option for UK users — not because of any commercial arrangement with the platform’s operators.
PolyGram gives UK users full access to Polymarket liquidity. No geoblocking, on-chain USDC settlement.
Open PolyGram →Real-time odds sourced from Polymarket · updated hourly