Polymarket US Tests Parlay Betting as Kalshi Rivalry Grows

Polymarket US has started processing multi leg sports contracts, commonly known as parlays. The platform kicked off testing on August 5 through a private API only beta, keeping the feature off its main consumer app for now.

The update highlights an effort to expand beyond single outcome prediction markets. Multi leg contracts let traders bundle several predictions into one trade for bigger potential returns, a format that drives massive volume in traditional sports betting.

The move comes as rival platform Kalshi builds serious momentum in the same space. Kalshi has generated tens of millions in fee revenue and is reportedly extending maker fees across its own parlay products. With both firms adding new products, competition for regulated US prediction market market share is heating up fast.