The house always wins, and online prediction markets are proving to be no exception—for now. Polymarket , one such offshore prediction site, allows users to place bets on topics such as the economy, sports, and most notably, political outcomes. The platform’s United States Presidential Election contest—where bettors could place wagers using cryptocurrency on either candidate—registered a staggering $3.2 billion in total trading volume before it eventually resolved in President-Elect Donald...