Prediction markets vs sportsbooks for Chiefs games: where the price comes from

Every Chiefs Sunday, two different kinds of venue put a price on the same game. They reach it from opposite ends, and the difference shows up in what a winning position pays. Chiefs fans on both sides of State Line Road can open both kinds, though in Missouri one of them is now in front of a federal judge.

How a sportsbook prices a game

A sportsbook is the other side of your ticket. It writes the line, takes every position against it and protects itself by shading both prices. A game it sees as a true toss-up does not go up at +100 each way; it goes up at -110 each way. Turn those two prices into probabilities and they add to about 104.8%. The excess is the book's margin, the vig or hold, and it is set before kickoff.

It never appears as a line item. It lives inside the odds. DraftKings' moneyline on Sunday's game, Jets at Chiefs, was Kansas City -550 and New York +410 as ESPN listed it Friday afternoon. As probabilities, those two prices sum to 104.2%: a hold of about 4.2% before anyone has picked a side.

How a prediction market prices a game

A prediction market does not take your position. It matches it. A trader who thinks Kansas City wins is paired with one who thinks it loses, and the price is wherever their orders meet, quoted in cents as a probability. A Chiefs contract at 84 cents pays $1 if the Chiefs win. With no house book to protect, there is no reason to shade the line, and the two sides of an active market usually sum to within a cent or two of $1.

The exchanges make money in different ways:

• Novig charges nothing on pre-game straight trades placed on its app or website. Live trades that take a resting order pay a taker fee of 0.06 × price × (1 − price) per contract in every league, NFL included, and traders whose resting orders are filled pay nothing, per Novig's fee schedule.
• Kalshi charges a taker fee scaled by price, built on a 7% rate. It is largest on a coin flip and shrinks as one side becomes a heavy favorite.
• Polymarket US sets fees market by market; check its schedule before trading.

The same game, three returns

Suppose the Chiefs trade at 84 cents on an exchange, close to the 84.6% that DraftKings' -550 implies.

On a heavy favorite the gaps are small in dollars, because the profit itself is small: 87 cents separates the no-fee trade from the sportsbook here. They widen on closer prices. On the spread, where both sides sit near even money, a 50-cent contract on the Chiefs covering returns $100.00 per $100 with no fee and $93.24 at a 7% rate, against $86.96 at DraftKings' -115. The exchange prices above are illustrations, not quotes; the board runs the same arithmetic on live prices for every Chiefs game and sorts each side from best return to worst. How to read the Chiefs board walks through the formula.

What it means in Missouri and Kansas

Missouri's sportsbooks are licensed by the Missouri Gaming Commission under Amendment 2, which voters approved in 2024, and have taken customers 21 and over since Dec. 1, 2025. They pay a 10% tax on adjusted gross revenue. DraftKings, FanDuel, BetMGM, bet365, theScore Bet and Fanatics, all on our board, are among the eight live apps, so those rows are prices a fan in Kansas City, Missouri, can actually take. Kansas, where many Chiefs fans live, has had its own legal sportsbook apps since 2022.

Prediction markets sit outside the state systems. The CFTC regulates them federally, and that is exactly what Missouri disputes. On Sept. 18, Attorney General Catherine Hanaway ordered six of them, Novig, Kalshi and Polymarket among them, to stop offering sports contracts in the state unless they get a Gaming Commission license. Novig and Crypto.com's exchange sued in federal court on Oct. 16, arguing federal commodities law preempts the state's gambling rules, and Kalshi filed its own suit later in October. No judge had ruled as of Friday, and Novig remains available in Missouri while its case is pending. Missouri sports betting in 2026 has the full picture, and the Missouri page prices this week's game at the venues a fan there can open.

Novig operates in 47 states, all but Arizona, Michigan and Nevada, so a Chiefs fan following the team to Atlanta on Nov. 15 or Buffalo on Thanksgiving night can still trade there. What new traders receive on sign-up is set out on the Novig offer page.

What "no fee" does not promise

No fee does not guarantee a better price. On an exchange the price comes from other traders and moves with them, and a thin market can show a wider gap between the best buy and the best sell than a sportsbook's built-in margin. When that happens it shows on the board, because the hold column measures every venue's two sides the same way. An NFL game draws more volume than almost anything else on an exchange, so the gap is usually small, but the board measures it on every refresh rather than assuming it.

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