Kalshi vs. the Sportsbooks: NFL Game Prices, Week by Week

A sportsbook prices one team to win a game at one number. Kalshi’s traders price the same side at another. Both numbers claim to say how likely that team is to win, but one of them costs less to buy, and the only way to know which is to put them on the same scale and compare.

This page does that for Week 2, matching 14 games where both a book line and a Kalshi quote exist. The average gap between the two prices runs 2 cents, and once Kalshi’s fee is added in, 13 of 28 sides priced at both venues come in cheaper on the exchange than at the books. The table below shows which sides those are, game by game.

Week 2: Kalshi vs. the sportsbooks

Where Each Price in the Table Comes From

The book side of the table starts with the consensus moneyline on the nflverse schedule feed. That feed carries the actual moneyline for each team, the number a bettor would see at a typical sportsbook, which already has the house’s vig built into it. To make that price comparable to anything else, it gets devigged: the vig is stripped out of both sides of the market so what’s left is the book’s fair probability, stated in cents on the dollar, the same way a contract is quoted.

Kalshi’s side of the table is its mid, the midpoint between the best bid and the best ask on the Yes contract for that team. It is also stated in cents, because a Kalshi contract pays a dollar if the team wins and the mid is the market’s running estimate of how often that happens. Putting the book’s fair price and Kalshi’s mid in the same units, cents per dollar of payout, is what makes the comparison possible in the first place.

None of this predicts who wins the game. It is a snapshot of what two different markets, one run by bookmakers and one run by an order book, currently think an outcome is worth. The gap column is the arithmetic difference between those two cents figures for the same side of the same game, nothing more.

How a Kalshi Price Actually Forms

Every NFL game on Kalshi is really two separate markets, one for each team. A Yes contract in either market pays a dollar if that team wins and nothing if it doesn’t. There’s no single line for the whole game the way a sportsbook posts one moneyline pair; each team’s contract trades on its own order book, with its own buyers and sellers.

That order book has a bid, the highest price a buyer is currently offering, and an ask, the lowest price a seller will accept. The mid sits between them and is what this page uses as Kalshi’s stated price. Traders who post those bid and ask prices are makers; traders who buy or sell right at those posted prices are takers.

Nobody at Kalshi sets the number. It moves because traders are buying and selling, the same way a stock price moves on order flow rather than on an analyst’s opinion. A team’s contract gets more expensive when more people want to buy Yes at that price than there are sellers willing to sell it there, and cheaper when the reverse is true.

That’s the core difference from a sportsbook, where a trader or a model sets the opening number and adjusts it based on what the book wants to happen to its own liability. On Kalshi, the price is only ever the last point where a buyer and a seller actually agreed.

The Fee, and Why the Mid Isn’t What Anyone Pays

Kalshi charges a taker fee of about 7% of a contract’s expected profit, and that fee is largest near 50 cents and gets smaller toward either end of the price range. A contract trading near 50 cents carries a bigger fee, $1.75 on 100 contracts at 50 cents, than one trading near 80 cents, $1.12 on 100 contracts at 80 cents, because a coin-flip price has more expected profit riding on it than a price that’s already close to a sure thing.

That fee is also why the mid isn’t the price a buyer actually pays. The mid is the middle of the bid-ask spread, a reference point, nothing more. A real buyer pays the ask, then pays the fee on top of it. So the number that belongs in a real comparison isn’t Kalshi’s mid at all; it’s the ask plus the fee, the all-in cost of actually buying the contract.

That’s exactly what the cheaper-after-fees column does. It doesn’t compare Kalshi’s mid to the book’s fair price, which would understate what a buyer pays on the exchange and overstate the book’s vig-free number. It compares Kalshi’s ask plus fee, the real cost of buying that side on the exchange, to the book’s own moneyline price, the real cost of buying that side at the sportsbook. Whichever number is lower is the cheaper side.

Why the Exchange and the Sportsbooks Land on Different Numbers

A sportsbook charges vig on both sides of its line and shades the number toward the side it wants action on and away from the side it doesn’t; it also caps how much any one bettor can put down. An exchange carries no house side at all. The fee is the only built-in cost, the other side of every contract is another trader rather than a book, and the ceiling on size is liquidity, how many contracts are actually resting on the book, rather than a limit set by management.

Those different mechanics mean the two venues can disagree even when they’re looking at the same game. A book’s traders have injury reports and beat-writer sourcing built into their process before the number is even posted; Kalshi’s price only moves once someone with that information places a trade. Early in the week, with less money on the exchange, that lag can leave a real gap between the two.

New Orleans Saints at Baltimore Ravens is this week’s clearest example. Kalshi’s mid on the Ravens sits 4.4 cents higher than the books’ fair price, 79.5 cents against 75.1 cents. Gaps like that tend to close as kickoff nears and more traders arbitrage the difference, buying the cheaper side on whichever venue is behind, but there’s no guarantee they close before the game starts.

When the Exchange Is the Better Buy, and When It Isn’t

There’s one test that matters here: is Kalshi’s ask plus fee below the book’s own price for that side? If yes, the exchange is the cheaper way to buy that outcome. If no, the book is, regardless of what the mid alone suggests. This week 13 of 28 sides pass that test in Kalshi’s favor, and 15 land the other way.

Underdogs and favorites both land on either side of that split, and which way it runs changes from week to week. A reader who bets a side because dogs are supposed to be cheaper on the exchange, rather than checking that week’s table, is guessing, not comparing.

A gap between Kalshi’s mid and the books’ fair price is a lean worth noticing, not a signal to bet. It says the two venues currently disagree about a probability. It says nothing about the actual cost of buying either side until the ask and the fee are added back in, which is why the table separates the gap column from the cheaper-after-fees column instead of collapsing them into one number.

Reading Volume and the Bid-Ask Spread Before Trusting a Price

Volume is the number of contracts that have actually traded, each worth at most a dollar at settlement. Open interest is how many of those contracts are still open rather than closed out. Together they show how much real money has taken a position, as opposed to how many people are simply watching a market from the sidelines.

New York Giants at Los Angeles Rams is this week’s most heavily traded matchup, with 515,787 contracts changing hands. A price built on that much volume, especially alongside a tight bid-ask spread, reflects a genuinely liquid market where a large number of traders have agreed to buy and sell around that number.

A wide spread means the next trade could land well above or below where the last one settled, so the mid in a market like that is a much softer number than the mid in a busy one. When a gap in the table lines up with a thin, wide-spread market, that gap deserves less weight than one sitting inside a heavily traded game.

The Weekly Routine, and What This Page Doesn’t Claim

The table is built for a short routine, repeated every morning through the week. Scan the gap column first for the sides where the exchange and the books disagree most. Then check the cheaper-after-fees column for whichever side is actually in play, since that’s the number reflecting real cost rather than raw disagreement. Finally, look at volume and the bid-ask spread before leaning on a price from a thin market.

Past weeks sit below the current table, under the Past weeks button, closed out with final results. They’re there to show whether a given week’s gaps actually closed by kickoff, and which side ended up right, so a reader can see how disagreements like this week’s have tended to resolve rather than take that on faith.

A few limits worth keeping in mind. The book price here is one consensus line, not a survey of every sportsbook a bettor could open an account with. Kalshi’s numbers are a morning snapshot that moves all day, so the ask a reader sees at noon may not match what’s shown here. None of it predicts who wins. It only compares what two venues charge to bet on it, and sports contracts are not available to trade in every state.