Polymarket vs Kalshi: The Quick Verdict
Polymarket has more markets and better liquidity on major events. Kalshi is regulated by the CFTC, accepts USD directly, and is the safer choice for US traders who want clean tax reporting. Neither platform is perfect. The right one depends on whether you prioritize depth of markets or regulatory simplicity.
We'll cover everything below, but if you want the short answer: US traders who care about compliance should use Kalshi. Traders who want the widest selection of markets and are comfortable with crypto wallets should favor Polymarket.
What Each Platform Actually Is
Polymarket
Polymarket is a decentralized prediction market built on the Polygon blockchain. You fund your account with USDC, browse hundreds of markets on politics, sports, economics, science, and culture, and trade shares in yes/no outcomes. It launched in 2020 and has grown into the most liquid prediction market on the internet, especially during major elections and geopolitical events.
It's not licensed as a regulated exchange in the US. American traders technically operate in a gray area, though many do participate through VPNs or by accepting the terms. That ambiguity has been a recurring issue.
Kalshi
Kalshi is a federally regulated exchange in the US, operating under CFTC oversight. That distinction matters enormously. You fund your account with dollars, trade event contracts (not crypto), and get proper 1099 forms at tax time. It launched publicly in 2021 and has been expanding its market offerings steadily.
The regulatory approval Kalshi fought for took years and faced serious opposition from traditional exchanges. They won. That makes Kalshi the only legal venue for US residents to trade event contracts on a regulated basis.
If you want to go deeper on Kalshi's specific market mechanics, our Kalshi weather trading strategy guide is a good next step.
Side-by-Side Comparison
| Feature | Polymarket | Kalshi |
|---|---|---|
| Regulation | Unregulated (decentralized) | CFTC-regulated |
| US residents | Gray area / restricted | Fully legal |
| Currency | USDC (crypto) | USD (fiat) |
| Number of markets | Hundreds active at once | Dozens to low hundreds |
| Liquidity | Higher on major events | Growing, thinner on niche markets |
| Fees | 2% fee on winnings | Bid/ask spread, small trading fee |
| Tax reporting | Manual (no 1099) | 1099 forms issued |
| Mobile app | Yes | Yes |
| Wallet required | Yes (MetaMask or similar) | No |
| Market resolution | UMA oracle + community | CFTC-compliant process |
Fees: Which Platform Costs More?
Polymarket charges a flat 2% fee on net winnings. There's no fee to enter a position, which feels clean. But 2% of profits adds up if you're trading frequently on tight edges.
Kalshi uses a spread-based model plus a small per-contract fee that varies by market. For actively traded markets, the spread tends to be narrow. For thin markets, you can lose meaningful edge just crossing the spread. The all-in cost is comparable to Polymarket on liquid contracts, but can get expensive on low-volume ones.
Neither platform is cheap compared to, say, using a prediction aggregator for information only. But both are reasonable for active traders who are finding real edge.
Markets and Liquidity
This is where Polymarket clearly wins today. The platform has deeper liquidity on major political and economic events, with order books that can absorb large trades without significant slippage. During the 2024 US election cycle, Polymarket was handling millions of dollars in daily volume. That kind of depth is useful when you want to enter or exit at fair prices.
Kalshi's liquidity has improved, but it still lags on many markets. The bid/ask spreads on less popular contracts can be wide enough to eat your expected value before the market even resolves. That's a real problem for systematic traders.
Kalshi does have some market categories that Polymarket doesn't cover well, particularly economic indicators like CPI releases, Fed rate decisions, and specific financial data points. If those are your focus, Kalshi is actually the better venue.
For serious geopolitical trading, pairing either platform with good research tools matters. We've covered the best AI geopolitical risk analysis tools separately, and several of them integrate naturally into a prediction market workflow.
Regulation and Legal Risk
We'll be direct. If you're a US resident, Polymarket carries meaningful legal risk. The CFTC has taken enforcement actions against prediction market platforms before. Polymarket settled with the CFTC in 2022 for operating an unregistered derivatives exchange. The platform subsequently blocked US IP addresses, though usage through VPNs continues.
If you use a tool like NordVPN or ExpressVPN to access Polymarket from the US, you're taking on legal exposure. We're not saying don't do it. We're saying you should understand what you're doing.
Kalshi is the opposite story. It fought the CFTC for years and won the right to operate as a designated contract market. Every trade is legal, regulated, and reported. If you ever face an audit or need to demonstrate that your trading activity was legitimate, Kalshi provides that paper trail. Polymarket does not.
User Experience
Polymarket has a cleaner, more modern interface. Browsing markets, checking probabilities, and placing trades feels fast and intuitive. The crypto onboarding (getting USDC into your wallet and connected to the platform) is the main friction point. If you've never used a crypto wallet, expect to spend 30 to 60 minutes getting set up.
Kalshi's interface is more conservative but equally functional. Onboarding is straightforward for anyone who's used a brokerage account. You connect a bank account, verify your identity, fund with dollars, and start trading. The process is familiar.
Both have mobile apps. Both apps are functional. Neither is as polished as something like Robinhood or M1 Finance in terms of mobile experience, but they're good enough for serious use.
Research and Analysis Tools
Neither platform provides sophisticated research tools built in. You're mostly on your own for market analysis.
Serious prediction market traders build their own research workflows. That often means pulling data from sources like Perplexity AI for fast factual lookups, using TradingView for markets that correlate with financial events, or setting up custom trackers in tools like Notion AI or ClickUp AI.
For traders who use quantitative approaches, QuantConnect can be adapted to back-test prediction market strategies, though the data integration requires work. We've seen traders combine prediction market positions with conventional financial hedges on Robinhood or through robo-advisors like Betterment and Wealthfront for portfolio balance. Our AI wealth management platforms review has context on how that kind of multi-platform approach can work.
Tax Treatment
Kalshi wins this one completely. As a CFTC-regulated exchange, Kalshi issues 1099 forms and treats contracts under established tax rules for futures. You know where you stand. Your accountant knows where you stand.
Polymarket gives you nothing. Every USDC transaction is technically a taxable event, and you're responsible for tracking your own cost basis, gains, and losses across every trade. Many traders use crypto tax software to handle this, but it adds complexity and cost. If you're trading at any meaningful volume, the tax headache on Polymarket is real.
Who Should Use Polymarket
- Non-US traders who want maximum market selection
- Traders comfortable with crypto infrastructure
- Anyone who wants to trade niche cultural or scientific markets that Kalshi doesn't cover
- Traders who prioritize liquidity on major political events
- People who want to trade large size and need deep order books
Who Should Use Kalshi
- US traders who want full legal compliance
- Anyone who wants simple USD onboarding with no crypto required
- Traders who focus on economic indicator markets (CPI, Fed decisions, jobs data)
- Anyone who needs clean tax documentation
- New prediction market traders who want a lower-friction starting point
Can You Use Both?
Yes, and many serious traders do. Kalshi for US economic and political markets where you want regulatory protection. Polymarket for international events, niche markets, or situations where Kalshi simply doesn't offer a contract.
Managing two platforms adds operational complexity. You need separate funding mechanisms, separate tracking, and separate tax accounting. But if prediction markets are a meaningful part of your portfolio, the diversification across platforms gives you more opportunity.
The Bigger Picture: Prediction Markets in 2026
The prediction market space has matured significantly. After the 2024 election cycle demonstrated that platforms like Polymarket could aggregate public information more accurately than traditional polls, both retail and institutional interest increased. Several hedge funds now trade on both platforms as part of broader information-gathering and hedging strategies.
Kalshi has been expanding its market categories consistently, and the gap in market selection between the two platforms is narrowing. Regulatory pressure on unregistered prediction markets may also increase, which would benefit Kalshi's regulated model.
For traders who approach this seriously, good research is everything. Using AI research tools to inform your probability assessments before entering markets is increasingly standard practice. Our AI research assistant comparison covers several tools that work well for this kind of analytical work.
Final Recommendation
If you're a US resident, start with Kalshi. The regulatory clarity alone is worth any trade-offs in market selection. As Kalshi expands its offerings, the case for using Polymarket as a US trader becomes harder to justify.
If you're outside the US, Polymarket is the better primary platform for most use cases. The liquidity is deeper on major markets, the interface is good, and the market selection is genuinely wider.
Either way, treat prediction market trading like any other speculative activity: size your positions based on your actual edge, keep records of everything, and don't mistake a string of winning trades for a systematic advantage.