Best prediction market
platforms — October 2026
Four venues do most of the volume, and they are not interchangeable. Two are exchanges, one is a US-only version of an exchange, and one is a brokerage reselling other people's contracts. Below is what each charges on the same trade, who is allowed to use it, and what you can automate. Every number links to the source we read.
◷ What changed since the last edition
Robinhood has priced commissions by probability since 2026-06-01 rather than charging a flat rate, which changes the cost of every trade away from 50¢ (Robinhood, 2026-10-21). It also started routing football contracts to Crypto.com and OG.com on 2026-09-08, alongside Kalshi, ForecastEX and Rothera (Robinhood, 2026-10-21).
Polymarket US replaced its fee schedule on 2026-10-19, with a 0.0695 taker coefficient and volume-tiered maker rebates (Polymarket US, 2026-10-21). Kalshi's schedule listed no upcoming fee changes when we read it, and its standard taker multiplier is still 1 (Kalshi, 2026-10-21).
Access moved too. Michigan residents could not open new sports event contracts at Robinhood from 2026-09-09 (Robinhood, 2026-10-21), and state-level sports blocks now apply to more than one venue (CoinDesk, published 2026-08-22). Treat eligibility as the first question, not the last.
→ How to pick, in the order that matters
- Eligibility decides for most people. Polymarket International is closed to the US and to a long list of countries; Polymarket US and Robinhood are US-only; Kalshi is the only one of the four that serves US residents and a set of international ones from the same account. If only one venue accepts you, the fee comparison is trivia.
- Then price the fee you will actually pay. All four formulas scale with
p × (1 − p), so they converge near 50¢ and diverge at the extremes. Price the trade you intend to make, not the headline rate — a 10¢ longshot and a 90¢ favourite cost a fraction of a 50¢ trade on every venue here. - Then check depth on the exact market. None of these venues publishes a comparable depth figure, and market counts are not depth. Open the market, look at the spread and the size on the touch, and ask whether your order survives it. Robinhood does not show full book depth at all, which is its own answer for size-sensitive trading.
- Only then consider automation. Kalshi and both Polymarket venues document APIs. Robinhood does not publish one for event contracts, and trading there is app-only, so any workflow you build around it is manual.
⊞ The comparison
Prices are per 100 contracts held to settlement, bought at 50¢, calculated with each venue's own published formula. They exclude the exchange fee that Robinhood layers on top, which is noted in its row.
| Platform | Fees | Market types | Eligibility | Liquidity signals | API access |
|---|---|---|---|---|---|
| Kalshi CFTC-regulated exchange | 0.07 × contracts × p × (1 − p), rounded up — $1.75 per 100 at 50¢ Standard multiplier 1. Maker fees are zero on most series and apply only on the ones the schedule names. Combos carry maker fees at 50% of taker. | Elections and midterms, politics, sports, culture, crypto, commodities, climate, economics, finance, tech and science, mentions. | US residents, plus the countries its Member Agreement allows — the restricted list is inside that document, not on the marketing site. Sports contracts are blocked in several US states. | Runs a Liquidity Incentive Program, and keeps maker fees at zero on most of the book — a signal it is buying depth rather than charging for it. | Yes. Documented predictions API with REST, WebSocket and FIX, plus a demo environment. |
| Polymarket International, on-chain venue | 0.04–0.07 × shares × p × (1 − p) — $1.00 per 100 at 50¢ in politics, $1.75 in crypto Makers are never charged. Geopolitics and world-events markets are fee-free, and there are no Polymarket fees to deposit or withdraw USDC. | Politics, geopolitics, sports, crypto, economics, finance, culture, tech, weather. | Outside the US, and only in countries its geoblock list still serves — the UK, France, Germany, Australia and Brazil are all restricted. Opening an account takes an email address or a wallet. | Taker fees fund a maker rebate paid daily in pUSD, so quoting is compensated rather than charged. | Yes. Documented CLOB API with SDKs; the same docs cover market data and order placement. |
| Polymarket US CFTC-regulated US venue | 0.0695 × contracts × p × (1 − p) — $1.74 per 100 at 50¢; table tennis 0.10 Maker rebate runs from −0.0035 to −0.0104 by volume tier and is applied at the trade; taker rebates are paid weekly by tier. | Sports including table tennis, crypto, politics and economics — the categories its own fee schedule prices. | US residents, with identity verification and a USD account. | Pays makers a tiered rebate and takers a weekly rebate, both scaled to the previous month’s volume. | Yes, but separate from the international docs — Polymarket US publishes its own documentation site. |
| Robinhood Brokerage reselling exchange contracts | 10% (5% with Gold) × contracts × p × (1 − p), capped at $0.01/contract — $1.00 per 100 at 50¢, before exchange fees The cap binds across roughly 28¢–72¢, so the commission is $1.00 per 100 there with or without Gold. Partners add their own fee, up to about $0.01 per contract, on opening and closing. | Sports and football, politics and elections, economics and financial data, crypto, climate and weather, commodities, entertainment, technology and education. | US residents 18+, with an individual brokerage account plus a separately approved derivatives account. Maryland and Nevada residents cannot trade sports contracts; Michigan residents could not open new ones from 2026-09-09. | Routes orders to KalshiEX, ForecastEX, Rothera and NADEX instead of running a book — 13.6 billion contracts traded in Q2 2026 across those venues. | No. There is no published event-contract API, and trading is mobile-app only — view-only on web, absent from Legend. |
100 contracts at 50¢: Kalshi $1.75, Polymarket US $1.74, Polymarket International $1.00 in politics and $1.75 in crypto, Robinhood $1.00 before exchange fees.
Robinhood's $0.01-per-contract cap makes its commission flat from roughly 28¢ to 72¢, then much cheaper toward 1¢ and 99¢. The others keep scaling with price uncertainty.
Makers on Polymarket International, always. Makers on Kalshi except on the series its schedule names. Polymarket US and Robinhood pay rebates or discounts rather than zero fees.
# What each venue is actually for
Written as audience fit, not as a score. Full profiles, with the sourced detail, are one click down.
Kalshi
CFTC-regulated exchangeBest forUS traders who want a regulated exchange, a bank rail, and the widest event menu.
Watch outPer-series fee exceptions and state blocks both change; read the schedule and the app, not a summary.
Polymarket
International, on-chain venueBest forTraders outside the US who want self-custody, crypto rails and politics or geopolitics markets.
Watch outIt is not one product: Polymarket US is a separate venue with separate fees, currency and users.
Polymarket US
CFTC-regulated US venueBest forUS traders who want Polymarket-style markets in USD with KYC and no wallet.
Watch outThe US fee schedule was replaced on 2026-10-19, so any comparison written before that date quotes numbers that no longer apply.
Robinhood
Brokerage reselling exchange contractsBest forUS Robinhood users who want event contracts inside an app and account they already have.
Watch outNo order-book depth in the app, no desktop trading, and no way to automate it.
+ The rest of the platforms
23 more platforms in the directory, including the on-chain venues and the brokers. Each links to a profile with its own access and pricing notes.
Blast-native prediction market with yield-generating positions. Acquired Probable in March 2026.
Decentralized prediction market with daily outcome payouts built on Base.
Crypto-native prediction platform on BNB Chain with zero trading fees. Acquired by Predict.fun in March 2026.
Play-money social prediction market with user-created markets.
Decentralized prediction market and futarchy protocol on Polkadot.
Permissionless prediction markets on Solana with high-speed execution.
Decentralized, trustless prediction market protocol on Ethereum.
Regulated forecast contracts from Interactive Brokers.
Parimutuel prediction markets on Optimism, Arbitrum, and Base.
Largest blockchain sports betting exchange with peer-to-peer trading.
Liquidity layer and infrastructure for decentralized prediction markets.
The multiplatform prediction market platform.
Yield-bearing prediction market platform on Polymarket.
Decentralized prediction market and oracle protocol on BNB Chain.
Prediction market platform on Sui blockchain with weekly prize competitions.
Decentralized prediction market for sports and real-world events.
Social prediction layer on Solana powered by Jupiter and Polymarket.
First futarchy governance protocol on Ethereum.
Margin account for Polymarket: up to 5x leverage, or borrow USDC against shares.
Native Hyperliquid prediction markets: leveraged outcomes with deep liquidity on HyperCore.
SORA-based binary prediction markets with KUSD collateral and pari-mutuel settlement.
Daily AI forecasts on politics, finance and geopolitics, benchmarked against Polymarket and Kalshi.
Prediction market platform covering politics, elections, economics, sports and global events.
↻ How this page is kept current
This is a monthly edition. The next one is dated 2026-11-01, and the edition date in the title is the date the facts were last checked.
Each edition re-reads the four fee schedules, the two eligibility pages, the API documentation, and the newsroom posts for routing and launch changes. Anything that moved is edited in place and the edition date is bumped. If nothing moved, the date still moves only after the sources have been read again.
Spotted a fee change, a country that should be listed differently, or a platform missing from the table? Tell us and it goes into the next edition.
↗ Sources
Every figure above traces to one of these. The date is when we read it, and where the source publishes its own effective date we note that too. Fee schedules are read from the venue itself, never from a summary.
- 1. Kalshi — Fee schedule (live page) checked 2026-10-21
Standard taker multiplier 1, fee range $0.07–$1.75 per 100 contracts. Page listed "no upcoming fee changes scheduled" when read.
- 2. Kalshi — Fee Schedule (PDF) checked 2026-10-21
Document states "Last updated and effective: July 7, 2026".
- 3. Kalshi — API documentation (REST, WebSocket, FIX) checked 2026-10-21
- 4. Kalshi Help Center — Can I trade on Kalshi from outside the United States? checked 2026-10-21
- 5. Kalshi — Member Agreement (restricted jurisdictions) checked 2026-10-21
The restricted list lives in Section VI and changes between versions; check the version date on the PDF.
- 6. Kalshi Help Center — Liquidity Incentive Program checked 2026-10-21
- 7.
- 8. Polymarket Documentation — Fees (category table) checked 2026-10-21
- 9. Polymarket Documentation — Geographic Restrictions checked 2026-10-21
- 10. Polymarket Documentation — Maker Rebates Program checked 2026-10-21
- 11. Polymarket Documentation — APIs, SDKs and tools checked 2026-10-21
- 12. Polymarket — live markets checked 2026-10-21
- 13. Polymarket US Documentation — Fee Schedule checked 2026-10-21
Taker coefficient 0.0695 (Table Tennis 0.10), maker rebate tiers, weekly taker rebates.
- 14. Polymarket US Documentation checked 2026-10-21
- 15. Robinhood Help Center — Event contracts overview checked 2026-10-21
Probability-weighted commission from 2026-06-01; eligibility and state restrictions on the same page.
- 16. Robinhood Help Center — Trading event contracts checked 2026-10-21
States prediction markets are mobile-app only, view-only on web, and not available in Robinhood Legend.
- 17. Robinhood Help Center — How event contracts work checked 2026-10-21
Lists the exchange partners in the disclosures.
- 18. Robinhood Newsroom — Robinhood Launches Prediction Markets Hub (2025-03-17) checked 2026-10-21
- 19.
- 20. Robinhood Newsroom — Teams Up With Crypto.com and OG.com (2026-09-08) checked 2026-10-21
Football contracts routed to OG.com from 2026-09-08; Rothera routing began in June 2026.
- 21. Robinhood Help Center — Market data sources for Robinhood Legend checked 2026-10-21
States event contract positions do not appear in Legend.
- 22. Robinhood — Developer documentation (Crypto Trading API) checked 2026-10-21
Covers the Robinhood Crypto Trading API only. No event-contract section.
- 23. Robinhood Learn — Prediction markets explained checked 2026-10-21
Its category guides (sports, politics, economics, climate, entertainment, technology, education, crypto) are the basis for the market-types column.
Nothing on this page is financial advice, and none of these venues pays for placement. Fees and eligibility change without notice — check them in the product before you trade, including the ones on this page.