Acrary is a genius!

Discussion in 'Strategy Building' started by greaterreturn, May 4, 2008.

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  1. I can't understand why diversification across uncorrelated strategies should not work.

    Suppose you have a rigged coin. 60% chance of heads and 40% chance of tails. Let's define "heads" as profit, and "tails" as loss. So by tossing this coin sooner or later you will be in profit (more heads than tails). It's just a matter of time (number of tries). The probability of being in profit after 20 tries is bigger than after 10 tries, right?

    Coin tosses are independent. Let's say we toss a coin 20 times a day. Take the first 10 and label them "strategy A", then the second 10 and label them "strategy B". The results of these two strategies will be uncorrelated, i.e. the strategies are uncorrelated. Now if you played only one strategy (A or B), you would get to toss a coin 10 times a day instead of 20, and the probability of you ending the day in profit will be lower.

    So how did that guy proved this does not work?
     
    #131     May 9, 2008
  2. monte4

    monte4

    countless examples can be given on this risk/reward and smoothness issue.
    for instance think that you are betting on a rigged coin flip, chances are 1/3 that you loose all your money and 2/3 for doubling it. if you bet all your money on one coin flip, the chances of facing losing all your money is 1/3 . if you diverse your money on betting 4 coin flips, this chance is reduced to 1/81. if this what you aim to do, then there is no problem, your strategy will work.

    there always can be unexpected events that can affect our investments, and by dividing our money on several investments we can reduce effects of this unexpected events. since we can't know everything, that our investments are affected by, in my opinion what greaterreturn has suggested is a wise thing to do, especially in times of uncertainties.
     
    #132     May 10, 2008
  3. man

    man

    actually it is the opposite with me, it adds to the unclear
    picture of what you are trying to bring across.

    if i have a trendFOLLOWING strategy in the sp500 and
    a trendFADER in the DowJones and we have a sudden
    move in both of them, then one strategy triggers a long
    and the other a short. if the two indices move on in the
    same direction i win with one, i lose with the other. so
    the ONLY thing i care about is strategy correlation. the
    underlying market corr does not tell anything, unless we
    are talking only about very similar strategies in the
    first place.
     
    #133     May 11, 2008

  4. Yes, this thread was originally started to discuss Alan's ideas. With this in mind, when people are talking about correlation, it's correlation among results of strategies, that enter long and short trades at different times, implement stop losses and other trade management techniques. Which is a lot different than correlations among price data series of different markets. But I would probably be wrong to assume that Maestro does not understand this.
     
    #134     May 12, 2008
  5. Jerry030

    Jerry030

    I wonder if things wandering so far off topic is a random or predictable phenomena?
     
    #135     May 12, 2008
  6. MAESTRO

    MAESTRO

     
    #136     May 13, 2008
  7. MAESTRO

    MAESTRO

    I definitely understand the difference. My point was related mostly to the multiple strategies scenario. However, correlation between the strategies usually stems out from the correlation of the data they are running on.
     
    #137     May 13, 2008
  8. Exactly, all we need now is the definition of the positive expectancy of correlated and noncorrelated confusion .After that all is just a walk in the park .
     
    #138     May 13, 2008
  9. MAESTRO, can you check your PM please.

    Thanks
     
    #139     May 13, 2008
  10. man

    man

    maestro

    (btw a great name. it is like talking to someone standing
    on a podium ...)

    i sense where you are coming from. yet i think in futures
    the additional sharpe outweighs the cost of leverage by
    far IMO. and i think this cost of additional leverage is
    what your argument boils down to ...

    one point comes to mind on the overall topic: if it is not
    nonCorrelated strategies, what the hell is a systemdeveloper
    looking for once he has something already trading?
     
    #140     May 13, 2008
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