[ralph84]

Even without insider trading it's a negative-sum game. Every dollar won is a dollar lost, and the platform takes a cut. Like all negative-sum games you should only participate if it's purely for entertainment or you have a clearly definable edge over the other players. If you can't spot the sucker, you are the sucker.

[UncleMeat]

People like to gamble. I expect that the vast majority of interaction with these systems is seen by participants as gambling. "Who will win the presidential election" and "who will win the jets game" are similar kinds of questions. Both are negative sum.

And people do get upset and feel cheated when the bet isn't "fair." We just saw a big scandal where various athletes are changing their behavior in order to enable their buddies to win big in sports betting.

I really don't think that "well, we should just educate people about the fact that prediction markets are actually battlefields of insider information and their purpose is not to enable gambling on the future but instead to give society some model of future outcomes" is going to stick.

[sadeshmukh]

To be clear, Polymarket has no fees on markets, only 15-minute crypto markets. That's probably temporary, but makes it a zero sum game at present.