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Compare the actual product and executable price, not just the brand name. A sportsbook quotes a bet at odds; an exchange-style prediction market matches orders for event contracts. Both expose money to an uncertain outcome, and neither guarantees an affordable early exit.
Brands can offer both kinds of product. FanDuel's product explanation distinguishes Sportsbook from Predicts and describes separate wallets, histories and promotions. Do not assume a feature or account balance carries between products. Sources checked October 6, 2026.
Compare price formats using the same payout
Suppose a hypothetical sportsbook quotes −110. Risking $110 wins $100 in profit, so a win returns $210 including the stake. The implied break-even probability is $110 ÷ $210 = 52.38%, before any additional costs.
A standard $1-payout event contract offered at 54¢ has a 54% break-even probability before fees. These headline numbers can be compared only if the winning conditions and exceptional outcomes match.
| Hypothetical offer | Cost per $1 winning return | Break-even probability before extra costs |
|---|---|---|
| Sportsbook −110 | About 52.38¢ | 52.38% |
| Event-contract ask 54¢ | 54¢ | 54% |
These independent illustrations are not observed offers or venue fee quotes. “Winning return” includes the original stake for the sportsbook calculation. Confusing profit with total return makes the comparison wrong.
The margin is not your forecast
If a hypothetical two-outcome sportsbook offers −110 on both sides, their implied probabilities sum to 104.76%. Normalizing both to a 100% total gives 50% each. That normalization removes the aggregate overround in this symmetric example; it does not prove the true probability is 50%.
The event-contract price is also not proof of the event's true probability. At a hypothetical 50% independent forecast, 100 contracts purchased at 54¢ have $50 expected payout against $54 purchase cost: −$4 expected value before fees. Stress-test assumptions in the EV calculator.
Inspect execution and exit conditions
| Check | Sportsbook product | Exchange-style event contract |
|---|---|---|
| Entry | Actual offered odds and stake limits | Actual ask/bid and available quantity |
| Early exit | Whether a cash-out offer exists and its price | Whether an opposing order can fill while trading is open |
| Costs | Margin in the quoted odds and applicable charges | Venue fees, spread and slippage |
| Settlement | Rules for the exact bet | Rules for the exact contract |
Polymarket US's spread guide distinguishes buying at asks from selling at bids. Kalshi's limit-order guide explains that a chosen price does not guarantee a fill. An order-book position therefore cannot always be sold at the displayed last price.
Even within prediction markets, interface labels differ. FanDuel Predicts' cash-out guidance says availability depends on liquidity and the quote can change. This describes Predicts, not every sportsbook's cash-out policy.
Match the rules before declaring one offer cheaper
Record the event definition, observation period, official source, postponement treatment, cancellation treatment and nonstandard payout conditions. A bet including overtime and a contract limited to regulation are not equivalent claims.
Use the contract-equivalence worksheet to test boundary scenarios, then the depth calculator to explore hypothetical fills. Neither tool verifies live prices or coordinates execution.
Keep access and classification separate from economics
Legal and regulatory treatment depends on product and jurisdiction. The CFTC registry identifies designated contract markets such as Kalshi and Polymarket US. An exchange listing does not by itself establish every person's access to every contract.
Research methods do not change a product's legal classification or eliminate its financial risk. Check current product terms and account availability rather than relying on a slogan about trading versus gambling.
A repeatable comparison
- Name the exact products on both sides.
- Normalize cost against the same winning payout.
- Include fees and executable size.
- Compare every settlement condition.
- Test downside and unavailable early exits.
Use Alphascope research to investigate the underlying event. Keep your forecast, access decision and order execution as separate checks.