Two platforms list what looks like the same event at different prices. Before you trust the gap, read the fine print. To compare prediction markets, you match the exact event, deadline, outcome states, resolution source, cancellation terms and fees, because similar titles can settle differently. The lesson builds a canonical record for each contract, then shows why buying YES at 47 cents on one venue and NO at 50 on another looks like a three-cent gain until fees turn it negative. You also meet basis risk, partial fills and different contract conventions. The skill is knowing when two prices are truly comparable and when the apparent edge is just mismatched rules.
Learning objectives
- Understand the mechanics and assumptions of this technique.
- Reproduce a worked calculation or decision worksheet.
- Identify cases when the evidence supports passing rather than trading.
