See arbitrages, asymmetric information, collusion, and price fixing

These are all effects of unregulated markets.

Markets aren't right or wrong. People decide what's right and wrong, and apply the relevant constraints via regulation.

Sure, I agree with that. It's not clear the comment I'm replying to does so. If we want to view the market as a phenomenon like soil erosion that's fine. I got the impression that the parent comment was implying markets as a provably optimal solver for resource allocation problems.