The trading volume on the leading prediction markets platforms, Polymarket and Kalshi, has hit a new record high, surpassing the previous peak reached during the US presidential election last year.The recent jump in trading activity offers one of the clearest indications yet of the growing excitement around the exchanges that allow investors to bet on the likelihood of real-world events, just as financial firms like CME Group Inc. and Intercontinental Exchange Inc. look for a way into these hot ...