Polymarket and Kalshi are the two biggest names in prediction markets, and on the surface they're twins: you buy Yes or No, prices sit between 0 and 100¢, and a winning share pays $1. The differences are in the details.
The quick comparison
- Regulation: Kalshi is a CFTC-regulated US exchange. Polymarket started as a crypto platform and has been expanding its regulated US offering. Which version you can use depends on where you live.
- Money: Kalshi uses regular dollars (bank or card). Polymarket's main platform runs on USDC, a dollar-pegged stablecoin.
- Fees: Kalshi charges a trading fee on most trades. Polymarket has historically charged no fees on most markets, but that has been changing for some market types. Always check before you trade.
- Markets: both cover politics, economics, sports and crypto. Polymarket tends to list niche and global events fast. Kalshi has deep economic and weather markets.
- Liquidity: the same event can have very different volume on each. More volume means tighter prices and easier exits.
Same event, different price
Here's the fun part. The same question often trades at different prices on each platform. Polymarket might have it at 58¢ while Kalshi has it at 52¢. Before you buy, check both. Grabbing the better price is free edge.
Careful though: "same question" doesn't always mean "same rules". A different source or deadline can make two similar markets resolve differently.
So which one?
- You're in the US and want plain dollars: Kalshi is the easy start.
- You want the widest range of markets and you're fine with crypto: Polymarket.
- You're serious about this: use both and always take the better price.
The bottom line
The platform matters less than your process. Compare prices on both, read the rules, mind the fees, and only trade when you can explain why the market is wrong.