On March 23, 2026, Kalshi and Polymarket, by far the largest prediction markets, announced bans on insider trading; even though insider trading is already banned in their Terms and Conditions. Prediction markets have two major problems, which can’t be cured by public...

I was recently quoted in an article published by Danish television network TV 2 Danmark examining the lawsuit between the State of Nevada and prediction market platform Kalshi. The case raises an important legal question: whether contracts allowing people to trade on...

Insider trading is illegal – in securities trading and regulated sports betting.  But it is actually one of the advantages that futures markets have over more conventional predictors.  If you want to know what is going to happen, give the opportunity to make big bets...