Regarding market efficiency.
I actually studied in Fama's class at U of Chicago (did not do very well in it, but did the whole class and passed). I thought that EMH was B/S, even then. It was our favorite topic for conversation among the students. By that time, I already owned some BRK/B shares.
The efficient market theory says that an investor (including or excluding insiders, depending on the version), cannot outperform a certain measure of "average market", despite doing diligent research, simulation, computer modeling, and so on.
Because it involves a negative, and is in some ways fuzzy, it is hard to disprove and is almost impossible to prove.
Fama was a very bright person and a scholar of EMH, but he never flat out said that he believed in it. He merely explored it in depth. So I would not say anything like "Fama is a fool".
Much has been written about EMH and many historical anomalies were found. With anything historical, it is very difficult to see if those historical anomalies, like low P/E investing and such, would repeat their outperformance the future.
Warren Buffett made a famous speech "The Superinvestors of Graham and Doddsville" where he very succintly debunked the EMH.
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He said, roughly, that he knows rather many individual people who consistently "outperform the market" by a wide margin. That, as such, is not at all a proof that this is not a random occurrence. But how come, he asks, so many of them come from Graham's Columbia value investing class? The possibility that this is a statistical fluke, is so minuscule as to not be seriously possible.
That means to me that there are people who are able to beat the market consistently, in a manner that is impossible to occur due to pure chance.
So the question of existence of "superinvestors" is a settled one, for me. I do think that EMH has been falsified beyond doubt.
That said, a much more pertinent question is: can a not-so-gifted, average intelligence Joe Blow, like myself, not bright like Buffett or Walter Schloss, busy with work and kids, and such, outperform the market?
This is a question that I considered and decided that I should not bother answering it, and, furthermore, I should not even try to outperform the market, such as S&P 500. I only make investments that make sense to me, and even more importantly, do not make investments that do not make sense to me.
Most of my investing career since 1996, until recently, was in a very difficult and overpriced environment, but at least I have not lost money and made some. (and did better than S&P 500, which is nothing to brag about in this environment).
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