For one, some people don’t know it’s rigged, while others think they can guess how it’s rigged and profit off it. I saw it a lot when I followed cryptocurrency scams - thousands of people bought into obvious pump and dump schemes because they thought they could time the dump and cash out before it hit. And even during the old analog days, tens of thousands of people bought into obvious pyramid schemes because they thought they were early enough to make a profit before the scheme collapsed.
The old saying “you can’t cheat an honest man” has a lot of truth to it, and degenerate gamblers are gonna gamble degenerately.
And for the prediction markets and the insider trading, it’s because people can’t. The online stuff uses anonymous throwaway accounts, and the more traditional insider stock trading only gets noticed when (if) the insider publicly reports their stock trades months or years later.
I had a theory about multiple accounts being connected to the same person and how they’d use that to hide their insider trading, but I did some digging, and in this case the trader is a single anonymous account which has a pattern of making winning bets - 16 of them - based on things Trump does:
https://www.binance.com/en/square/post/309527584561937
https://x.com/Mrminick_/status/2041170962368844105
So, yeah, you could make money by following this account and doing what it does, presuming you knew it had insider information, and presuming it doesn’t shut down now that people know it has insider information. After all, you want people to bet against you, and nobody wants to bet against the person with insider info, right?
Also, here’s an article with examples of apparent insider trading on oil futures, and explaining some of the ways multiple accounts can be connected to the same (anonymous) people:
https://www.msn.com/en-us/money/markets/insider-trading-claims-after-stock-and-oil-futures-surged-minutes-before-trump-s-iran-post