If there is a quantitative measure for Edge, what is it?

Discussion in 'Strategy Building' started by OddTrader, Jun 9, 2006.

  1. DrChaos

    DrChaos

    I like Acrary's methods.

    In modern statistics, Monte Carlo randomization types of tests are quite important and powerful. In my opinion, these types of things which can get at the real problem at hand, as opposed to a perfect analytic solution for a problem which isn't really the right one.

    You can, at a simple level, attempt bootstraps of your actual returns (bootstraps are a randomized sequence taken from the original time series, and you should probably use a method which includes whatever sequential correlation appears to exist) and then compare to bootstraps of returns from a "null" (zero expectation) series.

    You can get the second from randomized trading, or even just subtracting the sample mean of returns from yours (though that is 'less independent' in some ways).

    Then a figure of merit could be the fraction of times, and degree that bootstrapped returns (or cumulative sum thereof, or some measure including drawdowns) exceed the simulated returns from a no-skill setup.
     
    #41     Jun 10, 2006
  2. inCom

    inCom

    Maybe. However if I used little or no backtest at all, trading with my own money I'd risk to run out of it or spend too much time before I find profitable strategies. I try to regard backtest just as a preliminary phase in system development. Personally I used to believe much more in it than I do now.

    PS: I googled for "can be resulted" and "by probably due to" and found very few hits. I thought that 1) your written english is worster than mine or 2) you are kindly pushing my leg or 3) never mind, I'm wrong. :)

    GS
     
    #42     Jun 10, 2006
  3. Just 2 cents:

    I believe we can find and see a large number of papers covering this and related aspects for trading, although not knowing how many of the writers are profitable traders, whether before or after writing up their papers.

    How/ why are we going to decide using the 70% for long trades or 60% for short trades as mentioned by ACrary?

    How do we know these % figures are objective ones? Are they statistically significant, or arbitrary?
     
    #43     Jun 10, 2006
  4. Personally, I strongly recommend to do good backtesting - some Proper ones.
     
    #44     Jun 10, 2006
  5. ecritt

    ecritt

    How can you select at random (sample & replace) and maintain sequential correlation at the same time? I have always been under the impression that the two are mutually exclusive.
     
    #45     Jun 10, 2006
  6. cause it sounds great to a lot of losers.
    :D
     
    #46     Jun 10, 2006
  7. OddTrader,
    I like that. Of course, in my viewpoint, backtesting goes TOGETHER with system development. Point already often taken up at ET's: No competent profitable trader will ever reveal anything about either.
     
    #47     Jun 10, 2006
  8. Opra

    Opra

    Yes you are right. I shuold have included method/system in the list of "edges".

    All I was trying to say is, edge is not the steady upward-sloping equity curve, which is the result of a trader exploiting his "edges" here and there effectively.

    In other words, having "edges" does not garrantee trading success and lacking some "edges" does not spelll trading doom either. It all comes down to recognize one's strengths and weakness and trade accordingly.
     
    #48     Jun 10, 2006

  9. Everyone seems to be agreeing with ecritt's idea of quantifying edge. I havent gotten a chance to get the whole way through this thread, so i apologize if this has be mentioned already.

    While ecritt's idea is logical and probably mathematically correct, I believe it should not be pursued. In fact, quantifying an edge should not be attempted either. (Which is why it has little research on it)....

    Many traders seem to forget that the market is constantly changing, evolving, yada yada...this is why we all know that systems will eventually fail without modifications. The same applies to an edge. Its strength/weakness will constantly flucuate along with the market (unless you have the perfect system that adjusts to the market 100%). So quantifying your edge could only lead to a false sense of security making one believe his edge is stronger and more secure simply b/c it is defined. The quality of an edge will change as the markets change, therefore the only signifigant point is that you keep an edge at all times.

    ~RT
     
    #49     Jun 10, 2006
  10. Thanks for your revelation above.
     
    #50     Jun 10, 2006