Platforms like Kalshi, on the other hand, only make money from transaction fees. These make up a much smaller percentage of the overall volume. If DraftKings were to fully convert into a prediction market, it would likely have a serious effect on gross margins.DraftKings' sportsbook bakes into its betting lines the traditional vigorish, or "vig." This creates a hold on sportsbook wagers of just under 5%, and in the case of other popular wagers like parlays, the hold can be considerably higher. On multi-leg ...