Posted by OddsWatcher. I track market liquidity and resolution accuracy across regulated and offshore prediction markets. This is the comparison I keep getting asked for, so here it is in one place.
Prediction markets are betting. Call them "event contracts" if you want, but if you put dollars down on whether something will happen and you get more dollars back when you are right, you are betting. The question is which platform actually pays, settles cleanly, and is accessible from your state. Right now in 2026 the answer is almost always Kalshi or Polymarket, and they are very different products.
The fast version
Kalshi is regulated by the CFTC, runs in US dollars, and is legal in all 50 states for most markets. Polymarket is offshore, runs in USDC stablecoin on Polygon, and is officially blocked to US users. Kalshi is what you use if you want a clean tax form. Polymarket is what people actually use to get on the headline-grabbing markets that Kalshi will not list.
Liquidity and market depth
Polymarket wins on raw volume in headline markets. Presidential outcomes, Super Bowl winners, AI release dates, geopolitical resolutions. The 2024 US election cycle moved over $3.6 billion through Polymarket and the order books on flagship contracts were tighter than most regulated books.
Kalshi has caught up fast on sports and economic markets. After a 2024 court ruling cleared event contracts at the CFTC level, Kalshi added single-game NFL, NBA, MLB, and individual race markets through 2025 and into the current quarter. On those markets, Kalshi liquidity now rivals offshore books for the first six to twelve hours after a game lists.
For long-tail markets, Polymarket still has the edge. Kalshi's listing process is slower because of regulatory review.
Where you can actually play from
Kalshi is available in every US state. There are no state-by-state carveouts the way there are with sportsbooks. The CFTC framework treats Kalshi contracts as commodity derivatives, which sidesteps the patchwork of state gambling licenses.
Polymarket blocks US IPs at the platform level using KYC and geofencing. The block is real but porous. Most people in the US who use Polymarket connect via a VPN and a self-custody wallet. That is a violation of Polymarket's terms of service, and any market won there is technically uncollectable through normal channels because it leaves you outside the platform's recognized user base. The risk is not a knock at the door. The risk is your funds getting frozen if the platform tightens enforcement.
If you live outside the US, Polymarket is the better answer for breadth. Kalshi is fine for sports and macro events but its listings are tilted toward American interest.
Fees and payouts
Kalshi runs on a maker-taker model with fees in the 1 to 4 percent range depending on contract type. Withdrawals to a US bank are free and usually arrive in one to three business days. ACH limits are reasonable. Tax reporting is automatic via 1099-B at year end.
Polymarket charges no platform fees on most markets. The hidden cost is gas: every market interaction is a Polygon transaction. Polygon gas is cheap by Ethereum standards but it adds up if you trade frequently. Withdrawals are USDC to your wallet, which means you then need a separate route to convert to fiat. That extra step is where US users often run into friction.
Settlement and resolution
Kalshi resolves contracts based on a defined data source listed in the contract spec. The source is fixed before the contract opens. Disputes are handled through a CFTC-overseen process. In practice, Kalshi resolutions are clean. We have not seen a single high-profile resolution dispute on the platform in 2025 or 2026.
Polymarket uses UMA's optimistic oracle for resolution. A community proposes an outcome and a 24 to 72 hour challenge window opens. Most resolutions are uneventful but a small number have triggered prolonged disputes. The 2024 Venezuela election market had to be re-resolved after an initial UMA decision was overturned, and a few celebrity-event markets have had outcomes that did not match the spirit of the question.
If you cannot afford a 1 in 50 chance of a resolution dispute, use Kalshi.
The regulatory gap is closing
The CFTC under the current administration has signaled openness to expanded event-contract markets at Kalshi. New listings rolled out faster in Q1 2026 than in any prior quarter. If that trajectory holds, the gap between Kalshi and Polymarket on long-tail markets will narrow significantly through 2026.
Polymarket's path to a US re-launch depends on either a regulatory breakthrough or a different corporate structure. Both are possible. Neither is imminent.
Practical advice
If you are in the US and want to bet on prediction markets without legal complications, use Kalshi. The product is good enough now that the offshore detour is not worth the friction for most people.
If you are outside the US, sample both. Polymarket has more variety. Kalshi has cleaner settlement. The right answer depends on which markets you actually want to trade.
If you are curious but new, start with Kalshi for one US-relevant market you understand, like a single-game NFL line or a Fed rate decision. Trade small. Watch how the book behaves. The mechanics are simple but the discipline is the same as any other betting platform.
Related on rFactorCentral:
- Super Bowl 2025 predictions
- Is BetUS worth it for online sports betting?
Posted in good faith. None of this is financial or betting advice. If betting affects your finances or wellbeing, contact 1-800-GAMBLER (US) or your local equivalent.
Prediction markets are betting. Call them "event contracts" if you want, but if you put dollars down on whether something will happen and you get more dollars back when you are right, you are betting. The question is which platform actually pays, settles cleanly, and is accessible from your state. Right now in 2026 the answer is almost always Kalshi or Polymarket, and they are very different products.
The fast version
Kalshi is regulated by the CFTC, runs in US dollars, and is legal in all 50 states for most markets. Polymarket is offshore, runs in USDC stablecoin on Polygon, and is officially blocked to US users. Kalshi is what you use if you want a clean tax form. Polymarket is what people actually use to get on the headline-grabbing markets that Kalshi will not list.
Liquidity and market depth
Polymarket wins on raw volume in headline markets. Presidential outcomes, Super Bowl winners, AI release dates, geopolitical resolutions. The 2024 US election cycle moved over $3.6 billion through Polymarket and the order books on flagship contracts were tighter than most regulated books.
Kalshi has caught up fast on sports and economic markets. After a 2024 court ruling cleared event contracts at the CFTC level, Kalshi added single-game NFL, NBA, MLB, and individual race markets through 2025 and into the current quarter. On those markets, Kalshi liquidity now rivals offshore books for the first six to twelve hours after a game lists.
For long-tail markets, Polymarket still has the edge. Kalshi's listing process is slower because of regulatory review.
Where you can actually play from
Kalshi is available in every US state. There are no state-by-state carveouts the way there are with sportsbooks. The CFTC framework treats Kalshi contracts as commodity derivatives, which sidesteps the patchwork of state gambling licenses.
Polymarket blocks US IPs at the platform level using KYC and geofencing. The block is real but porous. Most people in the US who use Polymarket connect via a VPN and a self-custody wallet. That is a violation of Polymarket's terms of service, and any market won there is technically uncollectable through normal channels because it leaves you outside the platform's recognized user base. The risk is not a knock at the door. The risk is your funds getting frozen if the platform tightens enforcement.
If you live outside the US, Polymarket is the better answer for breadth. Kalshi is fine for sports and macro events but its listings are tilted toward American interest.
Fees and payouts
Kalshi runs on a maker-taker model with fees in the 1 to 4 percent range depending on contract type. Withdrawals to a US bank are free and usually arrive in one to three business days. ACH limits are reasonable. Tax reporting is automatic via 1099-B at year end.
Polymarket charges no platform fees on most markets. The hidden cost is gas: every market interaction is a Polygon transaction. Polygon gas is cheap by Ethereum standards but it adds up if you trade frequently. Withdrawals are USDC to your wallet, which means you then need a separate route to convert to fiat. That extra step is where US users often run into friction.
Settlement and resolution
Kalshi resolves contracts based on a defined data source listed in the contract spec. The source is fixed before the contract opens. Disputes are handled through a CFTC-overseen process. In practice, Kalshi resolutions are clean. We have not seen a single high-profile resolution dispute on the platform in 2025 or 2026.
Polymarket uses UMA's optimistic oracle for resolution. A community proposes an outcome and a 24 to 72 hour challenge window opens. Most resolutions are uneventful but a small number have triggered prolonged disputes. The 2024 Venezuela election market had to be re-resolved after an initial UMA decision was overturned, and a few celebrity-event markets have had outcomes that did not match the spirit of the question.
If you cannot afford a 1 in 50 chance of a resolution dispute, use Kalshi.
The regulatory gap is closing
The CFTC under the current administration has signaled openness to expanded event-contract markets at Kalshi. New listings rolled out faster in Q1 2026 than in any prior quarter. If that trajectory holds, the gap between Kalshi and Polymarket on long-tail markets will narrow significantly through 2026.
Polymarket's path to a US re-launch depends on either a regulatory breakthrough or a different corporate structure. Both are possible. Neither is imminent.
Practical advice
If you are in the US and want to bet on prediction markets without legal complications, use Kalshi. The product is good enough now that the offshore detour is not worth the friction for most people.
If you are outside the US, sample both. Polymarket has more variety. Kalshi has cleaner settlement. The right answer depends on which markets you actually want to trade.
If you are curious but new, start with Kalshi for one US-relevant market you understand, like a single-game NFL line or a Fed rate decision. Trade small. Watch how the book behaves. The mechanics are simple but the discipline is the same as any other betting platform.
Related on rFactorCentral:
- Super Bowl 2025 predictions
- Is BetUS worth it for online sports betting?
Posted in good faith. None of this is financial or betting advice. If betting affects your finances or wellbeing, contact 1-800-GAMBLER (US) or your local equivalent.