Overround, or vig, is the built-in margin when the prices of all outcomes in a market add up to more than 100%.
Understanding overround / vig helps you read prices and manage risk on any prediction market platform.
Example
If YES trades at 55¢ and NO trades at 52¢, the two sum to 107¢, meaning 7¢ of overround exists across the market.
Why it matters
Knowing how overround / vig works lets you compare markets and avoid costly mistakes when trading.
Practical tip
Before trading, check how overround / vig shows up on the specific platform you use, since interfaces and terminology can vary slightly between exchanges. Reviewing a few live markets is a quick way to see overround / vig in action before risking real funds.