There is 100% insider-trading and manipulation of prediction markets. It's absurd some of the markets that are created. The most glaring example was this years super bowl halftime show. They had markets on songs Bad Bunny would sing, which song he would sing first, etc. You're telling me the thousands of people who had access to practices and information would not wager on this?
You can just stand near the stadium during practice and glean this info. I believe people did exactly that.