They got the maths all wrong...

Discussion in 'Risk Management' started by earth_imperator, Jul 6, 2023.

  1. alistera

    alistera

    The height of the normal distribution has no relevance, only how painful it is for you but no one cares about that, the important numbers are the -4/3 and +3/4 sigma levels, success is defined how flat you keep the normal distribution peak between the minus and positive sigma, that is your entire trading journey, nothing more, nothing less, anyone saying anything different has less than no clue how to trade or invest.
     
    #11     Jul 6, 2023
    TheDawn, MACD and murray t turtle like this.
  2. Why not? I'm just researching, investigating, testing, questioning...

    Not true.

    Not true. Only TDA does it wrong.

    I just question everything, even my questioning everything... :)
     
    #12     Jul 6, 2023
  3. Sounds interesting (though "wild", IMO :)), can you say more about it, maybe with a real-world example?
    Do you rather mean the tails at "z=-inf to z=-3" and "z=+3 to z=+inf" ?
    They make up each just 0.1% or so, why do you think they are important? IMO not.
     
    Last edited: Jul 6, 2023
    #13     Jul 6, 2023
  4. Nothing is wrong with questioning or asking for clarification... but some humility won't hurt either!
     
    #14     Jul 6, 2023
    rb7 and murray t turtle like this.
  5. mervyn

    mervyn

    the height of the mode in a normal density is about 0.3989σ. google the formula, something like 1 divided by square root of 2 pie, if my recollection is still useful.
     
    #15     Jul 6, 2023
  6. Humility? I don't see any reason for it :)
     
    #16     Jul 6, 2023
    murray t turtle likes this.
  7. TheDawn

    TheDawn

    And when you want something clarified, try not to use thread titles like "they got maths all wrong" and and try to ask for verification in a question like "I believe the math for the margin calculation is wrong. Can somebody take a look at this for me?" If you still want people to verify for you, how do you know they've got maths all wrong? It's very likely that you are the one who's wrong.

    It also helps when you come with an attitude that people here are not as stupid in math as you think. The financial industry here is a lot more sophisticated than you think.
     
    #17     Jul 6, 2023
    rb7 and murray t turtle like this.
  8. For the CoveredCall(S=15, K=15, DTE=15, IV=30, r=0, q=0) I calculated pWin=0.657 :

    Premium=0.3639
    CostBasis=14.6361
    BreakEven_Sx=14.6361(-2.43% dz=-0.404)
    S_PL=0.3639(2.49% m=5.11%)
    K_PL=0.3639(2.49% m=5.11%)
    -1SD_Sx=14.1149 (-5.90% PL=-0.5212 (-3.56%))
    pWin=0.657

    Can anybody confirm this pWin?
     
    #18     Jul 6, 2023
  9. %%
    Sorry, if you have to learn everything the hard way, good road to ruin.
    Like the fossil fuels song says;
    from a mail order catalog\
    money made from sellin' a hawg [hog in butcher holler]:D:D Loretta Lynn Coal Miners Daughter. song > 14, 777,888 video views.
     
    #19     Jul 6, 2023
    ironchef likes this.
  10. upload_2023-7-6_11-58-40.png
     
    #20     Jul 6, 2023
    murray t turtle likes this.