Kalshi, Polymarket face U.S. scrutiny

- Prediction‑market firms Kalshi and Polymarket are racing to ban insider trading while users and rivals reallocate liquidity; FanDuel is pushing into the market space. - Kalshi claims roughly $37.5 billion year-to-date notional volume versus Polymarket’s $29.2 billion and has accused Polymarket of inflating volumes. - U.S. regulators are probing prediction sites for insider flows and national‑security risk, and economists openly debate whether informed bets are a feature or a problem. (cryptopolitan.com) (npr.org) (fortune.com)