DAVID MARCUS: Brave new world of prediction markets can make us all inside traders

When I was born in the 1970s, legal gambling was basically limited to Las Vegas, Atlantic City and horse racing. Then came Indian casinos, and finally, the floodgates opened with online gambling. Nowadays, with the advent of prediction markets, we can lay down a marker on almost any event on Earth. One serious upshot of the rise of companies like Kalshi and Polymarket, which would be happy to set up a market to see if Lindy’s sells more cheesecake or strudel today, is that far, far more people h