Polymarket Added Parlays. Prediction Markets Are Starting to Look a Lot Like Sportsbooks.

Polymarket has launched multi-leg contracts — its version of the parlay. Branded Combos and rolled out on May 22, the feature lets a user package several predictions into one position that pays out only if every leg hits.

The mechanic is exactly what parlay bettors know: the contract resolves to $1.00 if and only if all legs are satisfied, and $0.00 if any single leg misses. Package the legs, take one YES or NO position on the combined outcome, win it all or nothing.

Why this is a big deal

For most of its life, a prediction market was structurally different from a sportsbook — you traded single event contracts at market-set prices, not a house line, and the parlay, sportsbooks' most profitable product, simply didn't exist there. That distinction is now eroding. Polymarket added Combos the same month DraftKings and Kalshi pushed into multi-leg wagers of their own — three platforms converging on the parlay at once.

Polymarket paired the launch with an expansion into MLS markets — moneyline, spread, totals, props and futures — and a content distribution arrangement with Yahoo Sports. This is a crypto-native prediction market building out a full sports-betting product surface.

The catch, and the stakes

The legal ground is anything but settled. Polymarket faces more than 20 lawsuits and cease-and-desist actions, part of the same regulatory wave now battering Kalshi. Adding a product that looks even more like sportsbook betting — while arguing you are not a sportsbook — is a bold read of where the law lands.

For bettors, the takeaway is simpler: the once-clean line between "exchange" and "sportsbook" is disappearing, and the thing that made prediction markets interesting (trading a price, not fighting a house edge) gets murkier every time one of them ships a parlay. Worth watching closely, and worth understanding exactly what you're trading before you do.

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