Not in substance. “Combo” and “parlay” describe the same structure: a single position built from two or more event outcomes that pays out only if every leg resolves correctly. “Parlay” is the term inherited from sports betting. “Combo” is what prediction markets call the product: Kalshi named its multi-leg feature Combos, and Polymarket used the same name when it launched multi-leg trading in June 2026. The payout logic and the risk are identical. What actually differs between venues is how the combined position gets priced and traded.
Where Each Term Comes From#
Parlay comes from US sportsbooks, where it has meant a multi-leg, all-legs-must-hit bet for decades (UK bettors know the same thing as an accumulator or “acca”). When prediction markets started offering multi-leg products, traders and press naturally imported the word.
Combo entered the vocabulary as a product name: when Kalshi launched its multi-leg feature, it called the positions Combos, and the label stuck. Polymarket followed with its own Combos in June 2026, after its exchange entity QCEX self-certified Combinatorial Athletic Outcome Contracts with the CFTC on 20 May. Part of the reason the word travels is that these venues aren’t sportsbooks and the products aren’t legally framed as bets. On crypto-native platforms and on X, you’ll see both terms used interchangeably for the same position.
If one platform calls them combos and another calls them parlays, they’re talking about the same trade.
The Mechanics Are the Same. The Plumbing Isn’t#
| Attribute | Parlay (sportsbook usage) | Combo (prediction market usage) |
|---|---|---|
| Structure | All legs must hit | All legs must hit |
| Loss condition | One wrong leg = total loss | One wrong leg = total loss |
| Payout logic | Stake × the line the book set, margin in every leg | Stake × the price the market puts on the whole package |
| Who sets the price | The bookmaker | Traders or competing market makers, depending on the venue |
| Correlated legs | Often banned or repriced by the book | Priced (imperfectly) by the market |
The last two rows are the real difference, and it’s a venue difference, not a vocabulary difference. On an exchange-style prediction market, a multi-leg position is typically its own market: on Kalshi, each Combo has a dedicated order book and gets priced through a request-for-quotation, where other traders quote the opposite side. There’s no bookmaker margin compounding across legs; the price is whatever the market will bear. Polymarket runs its Combos through a market-maker RFQ as well (technical docs). One nuance from Kalshi’s combo rules: when a player doesn’t play, that leg settles scalar at its last traded price, and the combo pays the product of the leg values, so $0.70 × $1.00 × $1.00 pays $0.70 per contract instead of zero.
For how payouts, quotes, and correlation work, with a worked example, see what are prediction market parlays. Everything there applies to combos identically.
Which Platforms Use Which Term#
| Platform | Their term | Notes |
|---|---|---|
| Kalshi | Combos | Multi-leg positions priced via request-for-quotation; each combo is its own market |
| Polymarket | Combos | Launched June 2026 after QCEX self-certified them with the CFTC on 20 May as Combinatorial Athletic Outcome Contracts, starting with sports |
| Totalis | Parlays | Combines Kalshi and Polymarket event contracts into one onchain position settled in USDC on Solana; legs can span sports, crypto, politics, and tech |
| Sportsbooks (DraftKings, FanDuel, etc.) | Parlays / SGPs | Odds set by the book with margin in every leg; not prediction markets |
FAQ#
Is a combo the same as a parlay in prediction markets?#
Functionally, yes. Both describe one position made of multiple legs that pays out only if every leg resolves correctly. “Combo” is the label prediction markets use (Kalshi first, then Polymarket); “parlay” is the sportsbook term the rest of the market imported. Differences between venues are in pricing mechanics, not in the structure of the position.
What is a combo bet in prediction markets?#
A combo bundles several event contracts into a single position: for example, a game outcome, a points total, and a player result. The market prices the package as a whole, and it pays the full amount only if every leg hits.
Do combos pay out differently than parlays?#
No. Both pay a fixed amount if every leg hits and zero if any leg misses. The one nuance is on Kalshi, where a leg that settles scalar, a player DNP for example, adjusts the payout to the product of the leg values instead of zeroing it. Your payout multiple comes from the price you pay, which is quoted for the whole package rather than derived from a fixed formula. Venues differ in pricing mechanics, not in the payout structure.
Why does Kalshi call parlays combos?#
Kalshi is a regulated exchange, not a sportsbook, so it named its multi-leg product Combos instead of borrowing betting vocabulary. The name stuck across prediction markets, and Polymarket used it too when it launched multi-leg trading in June 2026.
Can one parlay combine markets from different platforms?#
On a single exchange, no. A Kalshi combo uses Kalshi markets and a Polymarket combo uses Polymarket markets. Totalis is the exception: one parlay can mix Kalshi and Polymarket event contracts in the same onchain position.
Is a combo the same as a same-game parlay (SGP)?#
Not quite. An SGP is a sportsbook parlay whose legs all come from one game. Combos are broader: legs can come from the same event or from completely different ones, including markets outside sports. Same-game combinations exist on prediction markets too, where the venue supports them.