Polymarket vs Kalshi: Full Comparison for 2026

Polymarket and Kalshi are the two dominant prediction markets available in 2026. Both allow users to trade yes/no contracts on real-world events, but they differ fundamentally in their regulatory status, available markets, fee structure, and the type of trader each attracts.

Understanding these differences is essential before deciding where to allocate your time and capital — or whether to trade on both platforms simultaneously.

Kalshi is a federally regulated exchange, operating under oversight from the CFTC (Commodity Futures Trading Commission). This means US residents can legally trade on Kalshi, deposits are held in regulated accounts, and there is a formal dispute resolution process.

Polymarket operates as a decentralised prediction market on the Polygon blockchain. It is technically accessible globally but its terms of service prohibit US residents. There is no CFTC or SEC oversight, and funds are held in smart contracts rather than regulated custodians.

For US-based traders: Kalshi is the legal choice for real-money trading. Polymarket involves regulatory ambiguity that traders should factor into their risk assessment.

Polymarket offers a broader range of markets — hundreds of active contracts at any time, spanning US and international politics, cryptocurrency, macroeconomics, sports, technology, and entertainment. The platform is especially strong on global and emerging-market political events that Kalshi doesn't list.

Kalshi has a narrower but more curated selection. Its markets tend to focus on US political events, Federal Reserve decisions, economic data releases (CPI, NFP, GDP), and corporate events. The benefit of this narrower focus: Kalshi's markets tend to have more institutional participation and higher quality resolution criteria.

For crypto, global politics, and niche events: Polymarket wins on selection. For US macro, Fed decisions, and regulated US political markets: Kalshi is more complete.

Polymarket consistently wins on liquidity for major markets. US election markets, Bitcoin price targets, and major international political events regularly process hundreds of millions of dollars. Tight spreads (1-2¢) on liquid markets mean transaction costs are minimal.

Kalshi has grown its liquidity significantly but still trails Polymarket on most market categories. The exception: Fed funds rate markets, where Kalshi benefits from institutional participation and can match or exceed Polymarket depth.

For a retail trader, the practical impact is this: on Polymarket's top 20 markets, you'll almost always get clean fills at quoted prices. On Kalshi, you may need to size down or accept wider spreads outside of its core markets.

Polymarket charges no explicit trading fee. The market maker earns the spread between bid and ask. For liquid markets, this effective cost is 1-2¢ per trade. There are also blockchain gas fees (minimal on Polygon, typically under $0.01).

Kalshi charges a fee on profits — currently 7% of net winnings, with volume-based discounts for active traders. For a high-conviction trade that generates $100 in profit, Kalshi takes $7. There are no fees on losing trades.

The math: for small-margin trades (e.g., 2-3¢ of edge), Kalshi's 7% fee can eliminate almost all your expected profit. Polymarket's spread model is more cost-effective for small-edge, high-frequency trading. For high-conviction, large-margin trades, the 7% fee is manageable.

Kalshi resolves markets using its own in-house resolution team with formal criteria documented at market creation. Disputes go through a CFTC-compliant process with defined timelines. This gives traders more legal recourse but also means resolution can be slower.

Polymarket uses the UMA (Universal Market Access) oracle for dispute resolution. Anyone can dispute a resolution by staking UMA tokens; disputes are resolved by a decentralised token holder vote. This process is typically fast (24-48 hours) but has on rare occasions produced counterintuitive resolutions on ambiguous criteria.

For markets with clear, objective resolution criteria (e.g., "did the Fed cut by 25bp at the November meeting?"), both platforms are reliable. For markets with subjective or ambiguous criteria, Kalshi's documented process provides more certainty.

Use Kalshi if: You're a US resident trading with real money, you primarily trade US macro and political markets, you want CFTC-regulated protection, or you prioritise institutional-quality resolution processes.

Use Polymarket if: You trade global events, crypto markets, or niche topics not listed on Kalshi; you want maximum liquidity on major markets; or you're outside the US.

Use both if: You find cross-platform pricing discrepancies to arbitrage, or you want access to the full universe of prediction market opportunities.

Use PaperPoly first: Before trading on either platform with real money, practice with PaperPoly's free paper trading. You'll get live Polymarket odds, $1,000 in virtual capital, and a full portfolio tracker — zero financial risk while you build your trading skills.