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dmh555's avatar

I didn't read Bessimbinder but had a gut feel that it contained the type of gross error that Paul points out.

I have an even stronger gut feel that the "most investments are bad" theme was A) true and B) irrelevant.

I carry about 50 tickers at any given time. Of those, there are always 3 or 4 "longshots". The investment size is small. I've had a couple of monster winners (20X) and a long list of losers. I'm slightly ahead over all, but that's not the point. The point is that if you accumulate ALL the total losses I've had, since every time one goes bust I go looking for another one, the list of bad investments keeps on growing while the number of tickers I am managing remains at about 50. The longer I do this, the larger the number of bad investments in the list. At some point I expect that the total number of bad investments I have made will exceed the number of good ones.

So despite "most" of my investments being "bad", I've got a portfolio that has trounced the S&P. I just feel like the premise as stated doesn't take into account the reality of how people actually invest.

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Brian Gerstein's avatar

I looked at the Bessimbinder study years ago and I strongly suspected that there was some flaw in it. The conclusions simply did not seem to be compatible with real-world results of investors. I searched online for potential critiques of the study, but I don't remember ever finding one. It seems that you found some of the problems which no one else ever noticed, or at least ever commented on. Thanks so much for this article which appears to have solved a mystery for me that I've been wondering about for years!!

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