Polymarket Cheapest on 67 of 110 NFL Lines (Oct 16)
Three venues, the same games, one frozen frame before kickoff: what each charged and why the structure behind the price matters.
Published 2026-10-16 · Data as of 2026-10-16 · Market & data intelligence · Educational, not advice.
Before Sunday's games, Delta Arc snapshotted 110 NFL lines across Kalshi, Polymarket and DraftKings. Polymarket held the cheapest price on 67, DraftKings on 33, Kalshi on 10. The gaps were small, usually a cent or two per dollar of payout. This explains what each price means, why exchanges and sportsbooks differ, and how the snapshot gets scored Monday.
Before Sunday's kickoff, Delta Arc's BM Dash froze a single frame of the NFL board and laid three venues side by side. Per Delta Arc's own calculation on public venue prices, it compared 110 lines across 14 upcoming games on Kalshi, Polymarket and DraftKings at 2026-10-16 13:54 UTC. This is what that one snapshot showed, and why the structure behind the numbers matters more than any one of them.
What a price actually means on each venue
Start with what you are buying. In Delta Arc's dash, each figure is the all-in cost of a $1 payout for a buyer, so lower is cheaper. On Kalshi that is the best ask plus Kalshi's taker fee. On Polymarket the quoted price already includes its fee. On DraftKings it is the implied probability of the posted American odds, vig included.
The deeper difference is what the price is a price of. Kalshi and Polymarket are exchanges: you take a position against another person, not against a house. Every contract has a buyer and a seller, the exchange matches them and collects a fee, and it never takes the other side itself. The price is simply where the most recent buyer and seller agreed, and it moves continuously until the game resolves.
A sportsbook works the other way. DraftKings posts its own number and holds the other side, with its margin built into the line. That is why its implied probability, drawn here from ESPN's odds feed, is not directly comparable to a raw exchange quote until you account for the vig. Comparing the three is price information, not a recommendation.
The fees are small but real. Per Kalshi's fee schedule, its taker fee is 0.07 times contracts times price times one-minus-price, rounded up to the next cent. Per Polymarket's documentation, its sports taker fee is 0.05 times shares times price times one-minus-price. Both shrink toward the extremes and peak near a coin-flip price, which is exactly where you would feel them most.
Where the cheapest price sat, line by line
Across all 110 lines, Delta Arc's dash found Polymarket held the cheapest all-in price on 67, DraftKings on 33 and Kalshi on 10. That is a count of where a buyer paid least at one instant, not a verdict on where anyone should go.
Between the two exchanges the pattern was cleaner. On the 80 lines priced on both Kalshi and Polymarket, Delta Arc found Polymarket cheaper on all 80, with a median gap of 1.3 cents per dollar of payout. Against the sportsbook the picture was more even: Kalshi came in cheaper than DraftKings on 30 of 78 comparable lines, per the same dash.
None of that tells you who wins a game. A venue being a cent cheaper on a contract is a statement about fees and order books at 13:54 UTC, nothing more.
How wide the gaps got
The spread between the cheapest and dearest venue stayed tight across market types. Delta Arc's dash put the median gap at 1.6 cents per dollar on moneylines across 28 lines, 1.2 cents on point spreads across 36 lines, and 1.2 cents on totals across 46 lines. In a market that settles at either 0 or 100 cents, a cent or two is the texture of the thing, not noise.
A few lines ran wider. Delta Arc recorded New England -7.5, in the New York Jets at New England game, at 47.8 cents on Polymarket, 49.0 on Kalshi and 51.2 on DraftKings. Las Vegas to win, hosting Buffalo, came in at 33.7, 35.0 and 37.0 across the same three. Kansas City to win, hosting the Los Angeles Chargers, sat at 79.5, 81.0 and 82.5.
At the top of the board, the dash flagged the weekend's biggest moneyline favorites as priced on Kalshi: the Los Angeles Rams to win at home against Arizona at 89.0 cents all-in, about an 89 percent implied chance with the fee; Kansas City at 81.0, roughly 81 percent; and San Francisco, hosting Washington, at 80.0, near 80 percent. A high-priced contract like that pays little because the market already treats the outcome as likely.
One frame, scored Monday
These are prices for a buyer at a single moment, not live readings and not a pick. Delta Arc saved this exact snapshot and will score these prices against the final results in a Monday follow-up on The Line, which turns a frozen board into a record you can check rather than a claim you have to trust. Robinhood is left out of this frame until its published commission schedule is reconciled with Delta Arc's cost model.
If you want to watch the same comparison move in real time instead of in a snapshot, Delta Arc's Prediction Markets product shows the live board across Kalshi and Polymarket in one place. The useful question before kickoff is never which number is right; it is why three venues, looking at the same game, land a cent or two apart. Monday will show how the frozen frame held up.
Sources: Delta Arc BM Dash; Kalshi's fee schedule; Polymarket documentation; ESPN's odds feed.
Sources
Outside pages cited in this post, in order of first citation
- Kalshi's fee schedulekalshi.com
- Polymarket documentationdocs.polymarket.com
- ESPN's odds feedespn.com
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