A prediction market is a priced, tradeable market; a sportsbook is a fixed-odds book. Polymarket shares pay $1.00 if an outcome happens and $0.00 if not — a $0.65 price implies roughly a 65% chance. You can sell before the event ends, which a fixed-odds bet does not allow.
That one difference — who sets the price, and whether you can leave early — explains most of the rest. This page compares the two on pricing, cost, what you can trade and regulation, and sets out the arguments on whether prediction markets are gambling without pretending the question has been settled.
This site is independent. It is not affiliated with, operated by or endorsed by Polymarket or any sportsbook. It is funded by affiliate referral, and nothing here is betting advice.
Prediction Markets vs Sports Betting: The Core Difference
A sportsbook sells you a wager at odds — a price it sets that reflects both its estimate of the outcome and the margin it keeps. You stake an amount, the bet sits open until it settles, and your payout is fixed at the moment you place it.
A prediction market sells you shares in an outcome. Every share pays $1.00 if that outcome happens and $0.00 if it does not, and shares trade at prices between $0.00 and $1.00, so the price itself reads as the market’s probability. A share at $0.65 implies about a 65% chance.
Two terms are worth fixing early, because they carry most of the comparison:
- Notional — the dollar value of a position at the current price. 100 shares at $0.65 is $65 of notional. Your maximum loss on those shares is what you paid; your maximum gain is the distance to $1.00.
- Resolution — the point at which the outcome is determined and shares pay out. Winning shares redeem for $1.00 each, losing shares for $0.00.
The practical consequence is that a bet and a market position are not the same instrument. Both put money at risk on an uncertain outcome, but only one of them has a live price you can act on before the event is over. We explain the share mechanics in more detail in How Prediction Markets Work.
Who Sets the Price?
A sportsbook sets its own odds. Trading desks and risk models move the line as money comes in, and the quoted prices are the book’s offer, not a record of what traders agreed to.
A prediction market’s price is set by its participants. On Polymarket the order book is hybrid: orders are matched off-chain and settled on-chain on Polygon, where positions are held as ERC-1155 tokens. Polymarket is non-custodial — it does not take possession of your funds.
That has three consequences worth knowing:
- There is no house line to beat. The price is where buyers and sellers are actually willing to transact.
- You can take either side of that transaction. A resting limit order makes you a maker — you are quoting a price for someone else to hit.
- The price can be wrong in your view. That is not a bug in the comparison; it is the point of a market. It is also why a thin market can show a wide spread between the best bid and the best offer.
The Vig Explained
The vig — also called juice or margin — is the commission a sportsbook builds into its odds. You never see it as a line item; it appears as a gap between the true chances and the prices on offer, and it is why the implied probabilities on both sides of a game add up to more than 100%.
The scale is not small. A $500 stake at a traditional sportsbook carries roughly $20 to $50 of implied vig — 4% to 10% — depending on the book and the market.
Polymarket charges differently: a published taker fee instead of a hidden margin, calculated as C × feeRate × p × (1 - p), where C is the number of shares and p is the share price. The fee peaks at a $0.50 share price and falls away toward both extremes. At the peak, per 100 shares:
| Category | Taker fee rate | Max fee at $0.50 |
|---|---|---|
| Politics, finance, tech, mentions | 0.04 | $1.00 |
| Sports, economics, culture, weather, other | 0.05 | $1.25 |
| Crypto | 0.07 | $1.75 |
| Geopolitics | 0 | $0.00 |
Applied to the same $500: on Polymarket that trade costs $0 to $17.50 depending on the category and the price, against the $20–50 of implied vig on the sportsbook side. Makers pay $0 and receive a rebate of 15–25% of the taker fees collected in the market.
Two fair points in the sportsbook’s favor. First, the vig is not pure profit — it pays for the book taking the other side of your bet, pricing risk and holding the position until settlement, which a market does not do for free. Second, the spread on a prediction market can cost more than a vig would. A wide bid-ask spread in a thin market is a real cost, and unlike a fee it is not published anywhere.
It is also worth knowing that an explicit fee is not unique to Polymarket. Kalshi, a CFTC-regulated US venue, charges a standard taker fee of 0.07 × contracts × price × (1 - price), and it rounds the order or fill total up to the next cent rather than per contract, so 100 contracts at 50¢ costs $1.75 rather than $2.00. The material difference is on the other side of the trade: Kalshi charges maker fees on many of its markets, while Polymarket makers pay $0 and earn a rebate. Our Polymarket vs Kalshi comparison covers that in detail.
Can You Sell Before the Event Ends?
A sportsbook wager is a commitment to settlement. Some books offer a cash-out, but that price is the book’s to set, and it can be withdrawn at its discretion.
A prediction market position is a tradable asset from the moment you own it. Buy 100 shares at $0.40 and the price moves to $0.70, and you can sell for $70 — a $30 gain on a $40 position, without the event ever happening. You can also exit a position you think has moved too far in your favor, or one whose thesis you no longer hold.
This is the difference that most of the “is it gambling” argument turns on. A wager is decided by an event you cannot influence. A position is something you can manage, price and close while the outcome is still unknown.
The caveat is liquidity. Selling at $0.70 requires a buyer at $0.70. In a deep market that is routine; in a thin one you may have to accept a worse price, or wait.
Fees Compared
| Polymarket | Kalshi | Traditional sportsbook | |
|---|---|---|---|
| How you pay | Explicit taker fee, charged at the match | Explicit taker fee | Margin built into the odds |
| Peak cost, 100 shares/contracts at $0.50 | $1.00–$1.75 by category | About $1.75, with the order total rounded up | Not itemized |
| Makers | Pay $0 and earn 15–25% of collected taker fees | Maker fees apply on many markets | No equivalent |
| $500 position/stake | $0–$17.50 depending on category and price | — | Roughly $20–50 of implied vig (4–10%) |
Polymarket’s deposit and withdrawal fees are $0 on its side, though intermediaries may charge their own. The full breakdown, including how the fee scales at every price, is in Polymarket Fees and the fee calculator.
What You Can Trade
A regulated sportsbook’s catalogue is sports. That is what its license covers, and it is the whole of what it offers.
A prediction market covers sports and then continues past it. Polymarket’s markets span politics, finance, tech, crypto, economics, culture, weather, geopolitics and mentions, along with sports. The fee table above lists the same categories, which is why a politics trader and a sports trader can pay different amounts for the same shape of trade.
One structural note for US readers: Polymarket International is close-only for US users, meaning existing positions can be closed but new ones cannot be opened. There is a separate CFTC-regulated US venue. Access rules differ by jurisdiction, and we do not assert a view on any state’s position.
Regulation: Prediction Markets vs Sportsbooks
Sportsbooks in the US sit under state-level gaming regulation, with each state licensing and supervising the books that operate within it. That framework has been settled for decades.
Event contracts are on a different track. In the US, Kalshi and Polymarket US are both CFTC-designated contract markets — Kalshi since November 2020, Polymarket US since December 2025. Being a designated contract market is a federal designation, and it is the framework the US venue operates under.
What is not settled is the state level. We do not state that prediction markets are legal or illegal in any particular state, because that question is being litigated and the outcome is genuinely open. For scale: a Washington state court issued a preliminary injunction in August 2026 with penalties of up to $120,000 per day, and Minnesota’s ban — passed in May 2026 — was enjoined by a federal court on 27 July 2026 in US v. Minnesota. A number of states beyond those two have taken positions, and the pattern is still moving.
Are Prediction Markets Gambling?
This is the question the whole comparison rests on, and it does not have a tidy answer. Both sides have an argument, and we are not going to pick one for you.
The case that they are gambling. You put money at risk on an uncertain future event. There is no underlying asset being produced or consumed, no dividend and no cash flow — the payout depends entirely on an outcome you do not control. Sportsbooks make this case, and some regulators have accepted it: multiple jurisdictions have classified event contracts as gambling or as unlicensed betting.
The case that they are not. An event contract is priced, tradeable and exitable. The price is discovered by buyers and sellers rather than set by a house, and a holder can sell before the event ends rather than waiting on a fixed-odds settlement. That is the behavior of a market in a claim, not a wager, and several operators — Polymarket among them — describe their venues on exactly those grounds.
Where this lands is unsettled law, not a settled fact. Whether US states treat event contracts as gambling is being litigated right now, and the answer may differ by state. If classification matters to your decision, treat it as an open question and check the current status where you live.
Are Prediction Markets Securities?
Also contested, and also unresolved — and here the relevant US regulator has been the CFTC rather than the SEC. The CFTC has taken the lead on event contracts, designating Kalshi as a contract market in November 2020 and Polymarket US in December 2025.
That is a real functional distinction: it means the US venues sit inside the commodity/derivatives framework rather than the securities framework. It is not the same as a definitive classification of every event contract everywhere, and none should be inferred. If you need to know how a specific contract or venue is classified, that is a legal question for the regulator’s own record, not something to take from an explainer page.
Who Each Suits
Neither venue is a better bet, and nothing here says otherwise. But the two structures suit different habits.
A sportsbook tends to suit you if you want a single fixed payout on a single event, you do not want to watch a price move after you commit, you would rather not think about spreads or liquidity, and the sportsbook is the venue that is licensed and available where you live. The transaction is simpler, and the cost is knowable up front.
A prediction market tends to be the better fit if you want to close a position before an event ends, you want to quote prices as a maker, you want to trade events outside sports, or you want to trade both directions on the same question. It asks more of you: you are choosing a price rather than accepting one, and you carry the liquidity risk of your own exit.
The honest summary is that a market position gives you more control and more decisions to make. If you do not want the second thing, the first one is of little use.
The Bottom Line
The difference between a prediction market and a sportsbook is not risk. It is structure.
A sportsbook sets a price, embeds its margin in it, and settles the bet when the event ends. A prediction market lets traders set the price, publishes its cost as an explicit fee, and lets you exit before resolution. Shares pay $1.00 or $0.00, prices read as probabilities, and the peak taker fee is $1.00–$1.75 per 100 shares against roughly $20–50 of implied vig on a $500 sportsbook stake — with the caveat that spread, not fee, is where a prediction market can quietly get expensive.
On the classification questions, the useful thing to hold onto is that they are open. Whether event contracts are gambling in a given state is being litigated in the US; the securities question is contested; the CFTC, not the SEC, has taken the lead on event contracts. Anyone telling you either question has a settled answer is telling you something the courts have not said.
If the structure is what you want, you can create a Polymarket account here.
- How Prediction Markets Work — shares, pricing and probability
- Polymarket Fees — how the taker fee is calculated
- Polymarket vs Kalshi — the same comparison against another CFTC-regulated venue
- Is Polymarket Legit? — the trust and safety side
- Fee Calculator — price out a trade before you take it