Research
Cross-Venue Spreads
The same bet is priced differently on Polymarket, Kalshi and Myriad. I wrote something to find matching pairs and see how far apart they get.
Three sites listing the same event should agree on the odds, and they don't. Before you can say whether that's worth anything you need to know which contracts are actually the same contract, which is harder than it sounds because none of them word a question the same way.
- Venues
- Polymarket, Kalshi, Myriad
- Matching
- Embedding similarity over question text, then a manual pass to confirm pairs
- Math
- Spread per matched pair, plus baskets where one event covers several contracts
- Testing
- Paper simulation over live sports markets
- Scope
- No real money. No order placement
Matching on question text alone kept pairing contracts that sound identical and settle differently. Two sites asking about the same game can disagree on what counts as a win, and if you miss that you're measuring a spread that isn't real. Every pair gets checked by hand now.