Self-regulating markets are just like self-documenting code.
To expand that beyond a cute quip -- as a programmer with 30 years of experience, I have learned that there is no such thing as self-documenting code. There are plenty of people who think code is self-documenting, but code without documentation is always less well understood, less correct, and causes more problems than the people who claimed it was self-documenting tell us we can expect. I say that as, I believe I can legitimately say, a qualified expert. I can't claim to be an expert on finance or economics, but I think that markets without regulation will always prove to be less well understood, less functional, and in the long run more trouble-prone than the proponents espouse. To continue the analogy, it is possible (even common) for documentation to be wrong, and when it is, it can definitely cause trouble, but the solution is to document correctly, not to stop documenting at all. Regulation can also be wrong, and I think a lot of the regulation we have today is, but it is foolish to expect good results if we remove all the regulation.