Kalshi vs Polymarket vs Manifold (UK & US 2026)

Kalshi, Polymarket and Manifold are the three platforms most users mean when they say "prediction markets" in 2026 - but they serve different audiences, run under different legal regimes, and use different settlement currencies. Kalshi is the US-regulated real-money option. Polymarket is the global crypto-settled option (banned to US residents). Manifold is the play-money platform with the most market-creation freedom. This comparison covers the regulatory status, market depth, fees, withdrawal mechanics, and UK / US availability of each, so you can pick the platform that matches your goals.

Prediction markets sit at an unusual intersection of derivatives trading, gambling law, and election interference concerns. The regulatory regime each platform operates under is the single biggest differentiator between Kalshi, Polymarket and Manifold - and it determines who can legally use the platform from which jurisdiction.

Kalshi (US-regulated). Kalshi operates as a Designated Contract Market (DCM) regulated by the US Commodity Futures Trading Commission. This is the same regulatory category as the Chicago Mercantile Exchange. Markets are listed as event contracts under CFTC rules. The regulated status brings FDIC-insured cash balances, mandatory KYC, ACH withdrawals, and a 25,000 USD per-market position cap. It also means Kalshi is legally available only to US residents - UK users are blocked at account creation.

Polymarket (no US, available globally). Polymarket previously operated unregulated US markets until January 2022, when the CFTC fined them $1.4M and required them to block US users. Since then, the platform has operated as a crypto-native (USDC-settled) prediction market available to non-US residents including UK users. There is no formal regulator overseeing Polymarket - it sits in a grey legal area outside the US that most jurisdictions tolerate but don't license. UK users can legally use Polymarket but the platform is not FCA-authorised.

Manifold (play-money, legal everywhere). Because Manifold's internal currency (Mana) cannot be cashed out to real money, it is treated as a video game or social platform rather than a gambling or derivatives platform. This means Manifold is legal worldwide with no regulatory friction. The trade-off is that there is no financial upside from being right.

Liquidity is the practical question that separates the three platforms once you've settled the legal question. The market depth determines how easily you can enter and exit positions without moving the price meaningfully.

Polymarket. By volume traded, Polymarket is the deepest prediction market in 2026 - top markets routinely settle $10M+ of cumulative volume, and large active markets have $500K-$2M of liquidity available within 1% of the mid-market price. The crypto-native settlement and lack of position caps attract larger traders. The 2024 US election cycle alone saw over $3.7 billion of volume on Polymarket according to publicly reported aggregate data.

Kalshi. Liquidity is meaningfully less deep than Polymarket but still credible for retail-scale trading. Top markets see $50K-$500K of typical depth within 1% of mid. The 25,000 USD per-market cap reduces the contribution of whale activity. Kalshi's market-maker programme provides baseline liquidity even on lower-volume markets.

Manifold. Shallowest of the three - top markets have a few hundred thousand Mana of liquidity, but most markets sit at low hundreds of Mana. Spreads can be wide on lower-volume questions. The play-money nature changes the incentive structure: users are forecasting for reputation and calibration practice, not for liquidity provision.

The practical guidance: if you want to deploy more than 5,000 USD or equivalent on a single position, Polymarket is the platform that can absorb it without significant slippage. Kalshi works for positions under 5,000 USD on most markets. Manifold is not the right tool for any size-driven thesis.

Kalshi: trading fees apply on profitable trades (the loser pays nothing). Typical fees are 1-2% of net profit on resolved positions plus a small per-contract fee (~$0.01-0.04). Withdrawals via ACH are typically free; wire transfers carry a $25-35 fee. The all-in cost on a profitable round-trip is meaningfully higher than Polymarket.

Polymarket: no platform fees on trades. The only cost is the bid/ask spread (which can be 1-3% on liquid markets, more on illiquid ones). USDC deposits via on-chain transfer cost gas fees (typically $1-3 on Polygon, the chain Polymarket uses). USDC withdrawals are similarly gas-fee-only. For active traders, this is the cheapest of the three.

Manifold: no fees at all. Mana is a closed-loop currency and Manifold operates as a non-profit - there is no economic incentive for fees. Users get free Mana on signup and can earn more by being calibrated forecasters or by creating popular markets.

The honest framing: Polymarket is the cheapest place to actually trade for active users, but Kalshi's fees are the cost of CFTC regulation and FDIC-insured balances - which is genuinely valuable for risk-averse users. Manifold's free model is structurally different because nothing has financial value.

Kalshi (USD via ACH): standard US bank ACH transfer, typically 1-3 business days. KYC verification (passport or driving licence + SSN + proof of address) is mandatory at signup. Wire transfers are available for larger withdrawals at a $25-35 fee. The withdrawal experience is identical to any regulated US brokerage.

Polymarket (USDC via on-chain transfer): withdrawal is an on-chain transaction from Polymarket's smart contracts to your USDC wallet (typically on Polygon, optionally bridged to Ethereum mainnet or other chains). Transactions are confirmed in 5-30 seconds and cost $1-3 in gas. From there, the USDC can be swapped to GBP via a UK-licensed crypto exchange (Kraken, Coinbase) and withdrawn to a UK bank account via Faster Payments. Total cash-out timeline is typically same-day for crypto-fluent users; first-time users may need 2-3 days to set up the off-ramp.

Manifold (no cash-out): Mana cannot be converted to real money. The platform is closed-loop by design. Some Manifold leaderboard prizes (sponsored prizes for forecasting tournaments) pay in real money, but they're occasional events rather than a standard withdrawal route.

For UK residents in 2026, the practical decision tree:

Want real-money exposure + comfortable with crypto wallets → Polymarket. This is the only legal real-money option for UK users. The USDC settlement mechanism and on-chain custody are an adjustment from a regulated brokerage but are well-documented and reliable. UK users are an explicitly served market segment on Polymarket - the platform's UK user base is substantial.

Want real-money exposure + uncomfortable with crypto → no good option in 2026. Kalshi is US-only. Smarkets and Betfair Exchange offer political markets to UK users but they're styled as sportsbook exchanges rather than prediction markets, with narrower question scope and worse liquidity on most non-sports events. Our prediction markets explainer covers the smaller UK-available options.

Want forecasting practice without financial risk → Manifold. The play-money structure makes Manifold the ideal place to develop calibration skills before deploying real money on Polymarket. Several published research projects use Manifold as a forecasting-skill training environment specifically because of this.