How event contract bundles are boosting volume on prediction markets

The growing popularity of a combo contracts on prediction markets is leading to soaring volumes, even as they makes up only a small amount of total activity on the platforms. Combos, or multiple contracts stacked together that only pay out if all of them win — similar to parlays on traditional sportsbooks — have exploded in popularity. Last month, combos accounted for more than 50% of notional volume on Kalshi , driven by the start of the NFL season . Combos are overwhelmingly made up of combinations of multiple sports contracts. As rival Polymarket worked to expand its U.S. exchange this year, combos were a priority following the domestic platform's official launch in May . Combos are now nearly 50% of daily volume on Polymarket U.S.