It really isn't at all like poker and really is a lot like the predetermined flow I'm just describing. Prediction markets regard the actions of politicians, sportspeople or businesspeople as indications of their wider goals for the country/team/business, not bluffs to try to influence their betting action. If a company says they're planning to IPO this year, everybody reasonably assumes that means the board want to make the IPO happen, not that they've already decided against it but reckon they can make a decent amount of spare cash anonymously betting against it happening on Polymarket