Quote from ssrrkk:
I guess you are saying Prof Andrew Lo must try harder, LOL. I just re-stated what he wrote in his chapters. I agree that it is rather absurd to use autocorrelation as the sole measure to represent the concept of "memory". I believe one needs to carefully identify the cases in which certain patterns work, sort of a conditional probability or Bayesian type approach. Of course, the reason academicians focus on the pure fundamental and simple estimators is because one can apply it to a large sample size to try to prove or disprove statistical significance. The truth is, in the business world, it is rare or impossible to find a significant trend that hasn't been exploited. We are left with patterns that may or may not be significant, but there is no way to prove it's significance given the amount of examples we have. In other words, making money will always entail risk.