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kleinbl00  ·  3535 days ago  ·  link  ·    ·  parent  ·  post: The Prudent Bear: The emerging markets picture darkens

I had, like six funds I invested with at the time. But yeah. Between 2003 and 2008 I increased my money 150%. Then between 2008 and now it's been in a ratcheting index fund. I may get creative again but right now? I like not thinking about it.

There's a great quote in "The Signal and the Noise" about the stock market.

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3. Efficient market hypothesis as an illustration of the Bayesian approach

Although Silver gives numerous examples of his Bayesian probabilistic approach to problems with numbers, one of his best examples is purely textual, on the efficient market hypothesis. He lists seven increasingly accurate, yet also qualified and probabilistic statements, on what we know about efficient markets.

The series of increasingly accurate, yet ‘less bold,’ statements are not only a great illustration of his big idea but also the right lesson for us on investing, so I reproduce it in full here:

a) No investor can beat the stock market.[6]

b) No investor can beat the stock market over the long run.[7]

c) No investor can beat the stock market over the long run relative to his level of risk.[8]

d) No investor can beat the stock market over the long run relative to his level of risk and accounting for transaction costs.[9]

e) No investor can beat the stock market over the long run relative to his level of risk and accounting for his transaction costs, unless he has inside information[10]

f) Few investors can beat the stock market over the long run relative to their level of risk and accounting for their transaction costs, unless they have inside information[11]

g) It is hard to tell how many investors beat the stock market over the long run, because the data is very noisy, but we know that most cannot relative to their level of risk, since trading produces no net excess return but entails transaction costs, so unless you have inside information, you are probably better off investing in an index fund.[12]

The first approximation – the unqualified statement that no investor can beat the stock market – seems to be extremely powerful. By the time we get to the last one, which is full of expressions of uncertainty, we have nothing that would fit on a bumper sticker. But it is also a more complete description of the objective world.