Been scanning Polymarket vs Kalshi and there are consistent arbitrage opportunities sitting there in plain sight. Same events priced at different odds across platforms with spreads of 4-6 cents after fees, expiring within 24 hours.
The inefficiency exists because these markets are fragmented and most traders stick to one platform. Low liquidity on certain events makes it even better, but position limits can be restrictive and you need accounts on multiple platforms with all the KYC and funding friction that entails.
I built pmxt to aggregate real-time data across platforms for exactly this. It's open-source if anyone wants to run their own scans: [https://github.com/qoery-com/pmxt](https://github.com/qoery-com/pmxt)
Currently supports Polymarket and Kalshi, working on adding execution next.
Anyone else trading prediction market arb? What's your experience with slippage and fill rates on smaller events?