Polymarket vs Kalshi: Which Prediction Market, and How to Find +EV Across Both

Polymarket and Kalshi are the two biggest prediction markets — both price events as true no-vig probabilities, but they differ on regulation, coverage, and where the sharp money lives. The real edge isn't picking one; it's line-shopping the same event across both for positive expected value.

Because Polymarket's flow is on-chain, it's where you can see the sharp money — which is why Cobia's smart-money engine runs on Polymarket. But the same event is often priced differently on Kalshi, and that gap is free +EV. Cobia devigs and compares both (plus Vegas) so you take the best available price.