Let us begin/POTO, while I am working on things, I'd like to point out that I am also not a fan of over-analysis. I think that what agip is saying is pretty much dead right, about hedge funds. I know 2 smaller fund managers, and their experience validates his comment.
So, while I bury myself for a while in equations like Fisher (which along with others I am completely capable of understanding, with lots of advanced university math), I see where they have their limits, and market prediction is one such area. Sure you can slice the baloney ever more thinly to weed out confounding factors, but then the range of applicability of your theorem is unusably narrow.
The markets are composed of a relatively small number of major players, and the rest of the players just play within the paradigm set by the big guys. Fine. Fun, and profit, can be had while restricting your play to a small area of the sandbox--but that's not what I'm interested in. What I am interested in is the aggregate markets, and what they have to say about the economy as a whole.
IMO when discussing things like this it is important to NOT let over-analysis, and too much rigor, cloud your vision. Intuition is great, as long as you have enough experience that it means something, and as long as you know who you are, to constrain the validity of that intuition.
I don't know about agip or about you, but although I do apply rigor to some things that I do, including what I am doing now, it is not the be-all and end-all of life as a social being.
You would be better off asking agip for more information about his pronouncements and then taking them for what they are worth, rather than constantly trying to point out an insufficiency of rigor.