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 r...