MargusPrediction markets let people trade on the outcome of real events, including NFL games, NBA games and Premier League matches. Margus tracks two of them, Kalshi and Polymarket US, and puts their prices next to sportsbook odds from DraftKings, BetRivers and theScore Bet so you can see who has the best number before kickoff. Margus does not take bets; it is a comparison and research site.
Affiliate disclosure: Margus may earn compensation from some outbound operator links. Commercial relationships never change which stored price ranks as best. Prices, availability and terms can change, so confirm them with the operator before acting.
Key takeaways
- Prediction markets are exchanges. Prices come from participants' orders, not from a bookmaker's odds.
- Prices are probabilities. A contract that pays $1 and costs 55 cents implies about a 55% chance.
- Fees replace vig. Exchanges charge trading fees on top of the price; sportsbooks build their margin into the odds.
- Both venues Margus tracks are on the CFTC's list of designated contract markets, but access depends on where you live. Check current status.
- The best price moves around. Sometimes an exchange beats the sportsbooks, sometimes not. Compare every time.
Our prediction market guides
- [Kalshi odds explained](/prediction-markets/kalshi): how Kalshi contracts and fees work, with a table of stored Kalshi prices against the best sportsbook price.
- [Polymarket odds explained](/prediction-markets/polymarket): Polymarket US's contracts and published fee formula, with the same sportsbook comparison table.
- [Kalshi vs Polymarket](/prediction-markets/kalshi-vs-polymarket): fees, liquidity, regulation and settlement rules side by side, and how to tell which has the better price for a given game.
What is a prediction market?
A prediction market is an exchange for event contracts. Each contract asks a yes-or-no question, such as "Will the Chiefs beat the Raiders?", and pays $1 to holders of the winning side. Traders buy and sell those contracts until a price settles where buyers and sellers agree.
Because the payout is fixed at $1, the price reads directly as an implied probability. A 70 cent contract implies roughly a 70% chance. That is the same idea as converting sportsbook odds into probability, which our implied probability guide explains step by step.
How prediction market prices compare with odds
Every price can be expressed in every format. Take a 55 cent contract:
- Implied probability: 55%
- Decimal odds (UK and Europe): 1 / 0.55 ≈ 1.82
- American odds (US): about -122
- Fractional odds (UK): about 9/11
If you are more used to one format than another, start with how to read odds. Once everything is on the same scale, comparing a Kalshi price with a DraftKings line or a Polymarket price with BetRivers is straightforward: for the outcome you want, the lower implied probability is the better price.
Prediction markets vs sportsbooks
The products feel similar but work differently:
- Who sets the price: a sportsbook sets its own odds; an exchange's price comes from its users.
- How they earn: a sportsbook builds a margin into the odds (what is vig?); an exchange charges trading fees on top of the price.
- Exiting early: exchange positions can often be sold before the event if someone wants to buy; sportsbook cash-out offers vary by book.
- Market range: sportsbooks usually offer many more props and alternative lines per game.
- Rules: settlement rules for draws, overtime and postponements can differ.
Our full guide to prediction markets vs sportsbooks goes deeper.
Fees and costs
Both exchanges publish their fees. Polymarket US uses a published formula where taker fees peak on contracts priced near 50 cents (fee schedule). Kalshi charges a transaction fee based on expected earnings, with some markets carrying different or maker fees (Kalshi fees). Fee schedules change, so check the live page for the market you are looking at, and always add fees before comparing an exchange price with sportsbook odds.
Regulation and availability
The US Commodity Futures Trading Commission lists both Kalshi and QCX LLC (d/b/a Polymarket US) as designated contract markets (CFTC list). How sports event contracts are treated at state level has been debated and can change.
For readers in the UK and Europe, both venues Margus tracks are US-regulated, and access depends on each operator's eligibility rules and your local law. Margus does not confirm eligibility for any location. Check the operator's current terms and your local rules first.
How Margus compares prediction markets with sportsbooks
On the Kalshi and Polymarket pages, Margus shows a table of upcoming NFL, NBA and soccer games in the next seven days where the exchange's market maps cleanly to a Margus event. Each row shows the exchange price, the best stored sportsbook price on the same outcome, and which is better. When nothing maps, the table is hidden rather than estimated.
To see the full sportsbook market for any game, use our odds hub, NFL odds and soccer odds pages. Comparing every available price is called line shopping, and our line shopping guide explains why it is the simplest long-term edge available. How we map events and pick best prices is documented in our methodology.
Prediction markets for football and US sports
US sports game markets usually line up well with sportsbook moneylines, so NFL and NBA games produce the cleanest comparisons. Football (soccer) needs more care: sportsbooks price home, draw and away, while an exchange "team to win" contract counts a draw as a loss. Margus only compares matching outcomes, but read each contract's rules before treating two prices as the same.
Play responsibly
Trading and betting both carry risk of loss. Set a budget, take breaks and never chase losses. Support and tools are on our responsible gaming page.
Guides
Frequently asked questions
What is a prediction market?
An exchange where people trade contracts on whether an event will happen. Contracts usually pay $1 if the outcome happens and $0 if not, so the price works as an implied probability.
Are prediction markets the same as betting?
They carry similar risk, but the structure differs. A sportsbook sets odds and takes the other side; a prediction market matches buyers and sellers and charges fees. Rules, fees and regulation differ too.
Which prediction markets does Margus track?
Margus stores prices from Kalshi and Polymarket US, alongside sportsbooks DraftKings, BetRivers and theScore Bet.
Are Kalshi and Polymarket legal?
The CFTC lists both Kalshi and QCX LLC (d/b/a Polymarket US) as designated contract markets. State-level treatment of sports contracts is contested and access outside the US depends on operator rules and local law, so check current status where you live.
Can I trade or bet on Margus?
No. Margus compares prices and provides research. It does not take bets, hold funds or place trades.
Are the prices on Margus live?
They are the most recent prices Margus has stored. Always confirm the current price, size and rules with the operator.