Prediction markets vs sportsbooks

A sportsbook is your counterparty and it wants your money. An exchange matches you against another trader and takes a fee for hosting the match. That single structural difference drives everything below.

A −110/−110 sportsbook line implies 52.4% on both sides — roughly 4.8% of built-in hold. An exchange quotes a bid and an ask in cents, so a market at 54/56 costs you the spread plus a fee, frequently less than the book's take on a liquid game.

This is the real difference. Buy a team at 48¢ on Tuesday, watch the market move to 61¢ by Friday, and you can sell for a 13¢ gain without the game ever kicking off. A sportsbook bet is locked until the final whistle unless you accept a punitive cash-out number.

Books limit or close accounts that win. An exchange has no risk desk making that call — your ceiling is how much size rests in the book, which is why thin mid-major markets cap real positions even when the edge is large.

Losing is still losing. A contract that settles at zero cost you the full purchase price, and no amount of market structure makes a bad probability estimate profitable. Sizing and selectivity carry the same weight in both venues.