Prediction markets vs sportsbooks

At a sportsbook, the house is your counterparty. It sets the line, takes your action, and profits when the book is balanced or when you are wrong. Its interests and yours are directly opposed.

On a prediction market, another trader is your counterparty. The exchange matches you and takes a fee regardless of who wins. It has no position in the outcome, which is why it can afford to publish an honest price.

A −110 line on both sides of a coin flip means the book's two implied probabilities add up to about 105%, not 100%. That extra five points is the vig, and you pay it whether you win or lose. It is invisible unless you convert the odds yourself.

A prediction market's two sides sum to roughly 100¢ because the price is meant to be the probability. The venue's cut is charged separately and visibly on the trade. Same idea — the house gets paid — but one of them lets you see the number.

This is the difference most people underrate. A traditional bet is locked until the event settles; a cash-out, where offered, is at the book's price and on the book's terms.

A prediction market position is a tradable share. If your team goes up 20 points and your 40¢ share is now worth 80¢, you can sell into the market and take the profit immediately, without waiting for the final whistle or accepting a discounted cash-out. Equally, you can cut a losing position before it goes to zero.

Sportsbooks manage risk by managing customers: consistent winners get limited or closed out, because the house carries the loss. It is a well-documented feature of the business model, not an accident.

An exchange has no such incentive — your profit comes from another trader, not from the venue. What limits you instead is liquidity: on a thin market you simply cannot get size on at a good price. Different constraint, and one you can see in the order book before you commit.

Honesty about the trade-offs matters. Sportsbooks offer far more markets, especially deep prop and in-play coverage, with instant liquidity on anything they list. Parlays exist because they are popular, and no exchange replicates them well. Promotions and bonuses have no equivalent either.

Prediction markets are better where the question is big, the volume is real and the price is the point — championships, awards, elections, macro outcomes. They are worse for a Tuesday-night player-props slate.