That's only true if you leave your money in...which you don't have to do.
You can play prediction markets by betting on a swing. E.g. I made a few hundred dollars betting on Harris in 2024 when Trump was at ~65% odds and then selling before the election when it was closer to 50%.
> can play prediction markets by betting on a swing
The outcomes are still capped. In that respect, it's more like a derivative market than the stock market. You can trade in and out of options. But the value in the system is tightly defined and, after fees, a net negative-sum game.
There is a fee implicit in the market spread. It's formed out of the time value of money w.r.t. the cost of NOT trading as well as the adverse selection faced by those with standing offers.
You can play prediction markets by betting on a swing. E.g. I made a few hundred dollars betting on Harris in 2024 when Trump was at ~65% odds and then selling before the election when it was closer to 50%.