Retail bettors are flocking to multi-leg bets on prediction markets, and skilled traders are feasting

Prediction markets just discovered what sportsbooks figured out years ago: nothing gets a retail bettor’s pulse racing quite like a parlay.

Polymarket launched its Combos feature around June 10-11, letting users bundle multiple prediction outcomes into a single bet that only pays off if every leg hits. Kalshi, its closest competitor, rolled out a similar offering and promptly racked up over $100M in volume within a single week of giving users full access.

How combo bets actually work

The mechanics are straightforward but worth spelling out. A combo bet multiplies the implied probabilities of each individual leg together. Three outcomes that each carry 50% odds? Your combined probability drops to 12.5%. The payout scales accordingly, which is exactly the point.

Polymarket uses a request-for-quote model for these combo bets, meaning market makers price each bundle individually rather than relying on a traditional order book. This creates an interesting dynamic: institutional traders and sophisticated market makers sit on one side of the trade, quoting prices to retail users on the other.

The numbers tell a painful story for retail

Retail prediction market users experienced a median return of -8% from mid-2025 to March 2026. That’s actually worse than the -5% median return on traditional sportsbooks over comparable periods.

Multi-leg bets make this dynamic worse, not better. Each additional leg compounds the house edge baked into the pricing. A market maker quoting a three-leg combo doesn’t just add a small spread once. They capture margin on every individual outcome, and the multiplicative math means those small edges snowball into meaningful expected losses for the bettor.

World Cup fever and a changing demographic

The 2026 World Cup has been a watershed moment for prediction market adoption. Combined offerings from Kalshi, Polymarket, and integrations with platforms like Robinhood hit record levels of engagement during the tournament, drawing in demographics that these platforms had previously struggled to reach. Female participation saw a marked increase, a notable shift for an industry that has historically skewed heavily male.

Total volumes across prediction market platforms have reached tens of billions during the 2025-2026 period. Robinhood’s integration with prediction markets has been particularly significant in driving mainstream adoption.

Polymarket’s planned POLY token remains unreleased as of July 2026. No new native tokens were introduced alongside the Combos feature.

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