Kalshi and Polymarket are the two biggest prediction market platforms, but they're fundamentally different in ways that matter to traders. One is a CFTC-regulated exchange trading in US dollars. The other is a crypto-native platform trading in USDC. Choosing the right one depends on what you're trading, where you live, and what you value.
The Quick Comparison
| Feature | Kalshi | Polymarket |
|---|---|---|
| Regulation | CFTC-regulated (US federal) | Not regulated in US |
| Currency | USD (bank transfer, debit) | USDC on Polygon (crypto wallet) |
| US Availability | Yes, most states | Officially blocked for US traders |
| Market Focus | Sports (90%), weather, econ, politics | Politics, crypto, current events |
| 2025 Volume | $43.1 billion | ~$9 billion (estimated) |
| API | Full REST + WebSocket | GraphQL + CLOB API |
| Fees | Per-contract trading fee | No trading fee (spread-based) |
| Fund Safety | Segregated at FDIC-insured banks | Smart contract risk |
| KYC Required | Yes (ID verification) | Varies by jurisdiction |
| Bot Trading | Supported, encouraged | Supported, heavy bot presence |
When to Choose Kalshi
- You're a US-based trader who wants regulatory protection
- You trade sports — Kalshi's sports market coverage is vastly superior
- You want weather and economic markets — Polymarket doesn't offer these
- You prefer USD — No need to deal with crypto wallets or stablecoins
- Safety matters — CFTC oversight, segregated funds, FDIC-insured banks
When to Choose Polymarket
- You're outside the US and want the deepest political/current events markets
- You want zero trading fees — Polymarket doesn't charge per-trade fees
- You're already crypto-native and comfortable with USDC/Polygon
- You trade political markets primarily — Polymarket's political market depth is unmatched
The Arbitrage Opportunity
For traders with accounts on both platforms, price divergences between Kalshi and Polymarket on the same event create arbitrage opportunities. When Kalshi prices "Democrats win" at 52¢ and Polymarket prices it at 48¢, there's a potential risk-free trade. These opportunities are increasingly competed away by bots, but they still appear in less-liquid markets.
Read our arbitrage guide for details on how to capture these.
Our Take
For US-based traders — especially sports traders or anyone building automated strategies — Kalshi is the clear choice. The regulatory protection, market variety, and API quality are superior. Polymarket is better for non-US traders focused on politics and crypto markets.
Many serious traders use both. Different platforms, different edges, more opportunity.
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