Polymarket and Kalshi are the two dominant prediction market platforms of 2026. Both let you trade on real-world event outcomes. Both have serious liquidity on major events. Both have track records that span multiple election cycles and major global events. But they are meaningfully different in ways that matter for your trading strategy. This is the most comprehensive comparison available — covering regulation, fees, market selection, liquidity, and user experience.
Regulation and Accessibility
Kalshi is regulated by the CFTC (Commodity Futures Trading Commission) as a designated contract market, making it the only major prediction market platform with full US regulatory clearance. US citizens can trade on Kalshi without the legal ambiguity that other platforms require.
Polymarket operates on blockchain infrastructure (Polygon network) and restricts access to US users due to regulatory concerns. Non-US users worldwide can access it, and it maintains the largest notional volumes globally. US-based traders looking for alternatives to Kalshi often use Polymarket through VPN arrangements, though this carries legal risk.
For US-based traders, Kalshi is the clear choice for compliance. For global traders, Polymarket’s larger notional values and broader market coverage often make it the primary platform.
Fee Structures
Both platforms charge fees, but their structures differ meaningfully.
Kalshi uses a maker-taker model where fees are charged per contract per side — entry and exit. The fee percentage depends on the probability of the outcome being traded. Overall fees typically range from 2-7% depending on market type, with lower fees on more liquid markets. This deducted from your profit when you close a winning position. Kalshi also pays interest on idle balances, adding a meaningful advantage for traders holding uninvested capital.
Polymarket’s fee structure is built into the spread between buying and selling prices, with explicit fees ranging from 0-2% depending on the market. The platform is crypto-native (USDC on-chain), so costs also include conversion and on-ramp fees that vary by user location and method.
For high-liquidity markets with tight spreads, Polymarket’s effective fees are often lower. For niche or thinly-traded markets, Kalshi’s transparent percentage fee can be easier to model and anticipate. High-frequency traders often find Polymarket cheaper overall; traders who value fee transparency and interest on balances tend to prefer Kalshi.
Market Selection
Polymarket currently lists more markets than Kalshi across virtually every category. Its community governance model allows for faster market creation, meaning emerging events often appear on Polymarket first. This breadth comes with a tradeoff: some Polymarket markets are quite thin, with low notional values that make them unreliable as price signals.
Kalshi’s regulated environment requires more rigorous market approval processes, which limits breadth but improves average market quality. Kalshi markets tend to have clearer resolution criteria, which reduces resolution risk. The platform has particular depth in US political and financial markets given its regulatory profile and US user base.
For traders who prioritize market variety and the ability to find obscure opportunities: Polymarket. For traders who prioritize market quality, clear resolution criteria, and regulatory safety: Kalshi.
Liquidity Comparison
For major global events — US presidential elections, major central bank decisions, World Cup finals, Bitcoin price milestones — Polymarket typically shows higher aggregate notional values. This reflects its larger and more internationally distributed user base.
For specifically US-centered events — congressional races, US regulatory decisions, major domestic economic data — Kalshi’s notional values are increasingly competitive, and in some categories have surpassed Polymarket.
Prediction Terminal displays notional values from both platforms simultaneously, allowing you to quickly identify which platform has deeper liquidity for the specific market you’re analyzing. Always check notional before trading — the platform with the higher notional is generally offering the more reliable price signal.
Which Platform Is Right for You?
Choose Kalshi if you are US-based, prioritize regulatory compliance, prefer clear resolution criteria, and are primarily interested in US political and financial markets. Kalshi’s CFTC regulation provides a level of institutional trust that matters if you’re deploying significant capital.
Choose Polymarket if you are non-US-based, prioritize market breadth and global liquidity, and are comfortable with the blockchain-native trading interface. Polymarket’s larger global notional values make it the most liquid venue for major international events.
The best approach for serious prediction market traders is to use both — and Prediction Terminal to compare them. The platform with better odds and deeper liquidity varies market by market. Checking both before every trade is the simplest consistent edge available.
Compare Polymarket and Kalshi live on Prediction Terminal.
Frequently Asked Questions
Is Kalshi or Polymarket better for US traders?
Kalshi is the clear choice for US-based traders due to its CFTC regulation and full legal compliance. Polymarket technically restricts US users, and accessing it carries legal risk. For non-US traders, Polymarket’s larger notional values and broader market selection make it the primary platform.
How do Polymarket and Kalshi fees compare?
Kalshi charges 2-7% of winnings depending on market type, with transparent fee accounting and interest paid on idle balances. Polymarket fees range from 0-2% explicitly, with additional crypto on-ramp costs. High-frequency traders in liquid markets often find Polymarket cheaper; traders valuing transparency and balance interest prefer Kalshi.
Which platform has more markets — Polymarket or Kalshi?
Polymarket lists more markets across virtually every category, with faster market creation through community governance. Kalshi has fewer markets but higher average quality, clearer resolution criteria, and particular depth in US political and financial event categories.