Thing is, is that bubbles and busts may not actually be irrational. Don't dismiss the idea immediately!I don't think of EMH in the way some people do, as in "The Price Is Always Right" philosophy, which is a misguided interpretation of the very basis of the conceptual framework of EMH in my opinion. It's like saying Evolution is the survival of the fittest, it's a soundbite, a too drastic simplification, not a real piece of information.My view is that EMH is about "global level efficiency". To use an analogy, in globalization there are winners and losers, but the net effect of globalization is greater output for less input i.e. GDP growth. This is despite the obvious fact that jobs and entire industries, maybe even whole countries are devastated by global competition, which gives a highly misguided impression of the big picture that many people find hard to get their heads around mainly for psychological reasons, which is why the national socialists capitalize on this despite the greater egalitarianism that globalization brings. Define irony, there it is. Globalization implies the rise of Fascism, there's an ugly idea.Similarly, these "inefficiencies" people claim to see in EMH are actually local, not global. Not only that, but these local occurrences are highly transitory and peculiar in nature, by which I mean it is nearly always impossible to find the liquidity to make genuine trades to exploit those arbitrage possibilities, most EMH 'inefficiencies' written about in whitepapers are retrospective, which does not improve my opinion of the economists who write them.We understand of course there is somewhat of a strange paradox that is difficult to fully articulate (that there are reasons why certain whitepapers won't be published...), but I think all participants in the markets can intuitively see the phenomena I mean even if they describe it using completely different language.A good example of this is the concept of Value. The truth is that if EMH was completely true i.e. strong form efficiency, then people like Warren Buffet would be out of business.The truth is also that if EMH was completely wrong, then Buffet's stock would never have had a northward bias in the first place.This points to efficiency being a global phenomena. It is like when you stamp down into a puddle of water, the sides may surge upwards, but the main story is that a volume of air has mostly displaced a bunch of water in the middle. The droplets rain around, touching off little minor versions of the stamping of the puddle, but this information is completely junk, it is just a tiny mirror of a huge movement that is invisible.So something much stranger is going on, and it's not necessarily even weak form EMH either, I think it's a much more hairy thing, I look forward to the new economic theories in the 21st century, I think we're in the path of a huge upset or two that may not appeal to anybody in either camp.In particular I am struck by the convergence of the studies of Artificial Intelligence and Market Efficiency. I think I see a future where we see a New Synthesis between these fields of scientific endeavor which may bring startling observations about what it really means to be human.--Finally, my view is that people who think they can make a killing on markets, any markets, just because there could be inefficiencies are extremely misguided.Even if EMH is completely wrong, it does not follow for one second that you'll make money on markets. You may indeed do so. But it's a two sided coin, an implicit bet on markets going from inefficient to less inefficient. If you're putting money in, and you're right, and it goes in the other direction, then what? You are then depending on the roulette wheel.tldr; Quote"In the short run, the stock market is a voting machine, but in the long run it's a weighing machine." -- BG