Both let you put money on a game. But a sportsbook and a prediction market are built in completely different ways, and that changes how you should use them.
The big difference
- DraftKings (sportsbook): you bet against the house. It sets the odds and builds its margin into every line.
- Polymarket (prediction market): you trade against other people. Prices move with supply and demand, and you can buy or sell any time before the event ends.
Side by side
| Polymarket | DraftKings | |
|---|---|---|
| Who sets the price | Other traders | The sportsbook |
| Odds format | 0–100¢ (= probability) | American odds (-110, +150) |
| Exit before the end | ✅ Sell at market price | ⚠️ Cash out at the book's price |
| Cost to you | Spread and fees, varies by market | Margin built into every line |
| Markets | Sports + politics, economy, crypto, culture | Mostly sports, huge prop menus |
| Availability | Depends on your country or state | Where legal, mostly US states |
When each one makes sense
- Polymarket: when you want to trade in and out, when the price looks off compared to the books, or for non-sports events.
- DraftKings: for props, same game parlays, live betting and promos.
The pro move
Compare the two. If Polymarket has a team at 52¢ (about 52%) and a sportsbook has them at +110 (about 47.6%), one of them is mispriced. That gap is your edge.
Key takeaways
- Sportsbook = you vs the house; prediction market = you vs other traders
- Polymarket prices are probabilities you can sell before the end
- Comparing both is how you spot mispriced lines
The bottom line
They're not rivals, they're two tools. Use each one for what it's good at, and use the difference between them to find value.