Should we trust Vega calculations?

Discussion in 'Options' started by candeo, Feb 16, 2007.

  1. candeo

    candeo

    Rallymode,

    TOS can model each strike independantly. Just click on the wrench and then on "more".
    Anyway, for those of you interested, I just had a long chat with TOS's support, and they confirmed what I was saying:

    Their model accurately predicts future IV's and P/L EXCEPT around earnings/FDA announcements etc..
    So for example a RC will NOT profit from IV crush, even if this is what their model is showing.
    Scriabinop, we should not use the "volatility steps" in their model. Of course, we can always change each IV independantly but this requires some guessing. Of course for longer term plays their calculations are correct, and a RC would profit from IV crush over the long term.
     
    #21     Feb 21, 2007
  2. MTE

    MTE

    Exactly, modelling future PnL requires a lot of guessing, both for volatility and stock price. The model is only as good as are the assumptions/inputs, so if your assumptions are wrong then your modelled PnL will be significantly different from the actual one, but that doesn't mean the model is broken, it just means you used the wrong assumptions.
     
    #22     Feb 21, 2007
  3. Great, i didnt know that. Maybe i should reopen my acct.
     
    #23     Feb 21, 2007
  4. MTE

    MTE

    TOS can model each expiration independently, not strike.
     
    #24     Feb 21, 2007
  5. I suspect TOS didn't tell you that verbatim.

    If they did I need to find out where that button is.....LOL.
     
    #25     Feb 21, 2007
  6. candeo

    candeo

    You know what I mean: they estimate future IV's and P/L depending on the move of "entire IV" that you anticipate.
     
    #26     Feb 21, 2007
  7. yeah, I knew what you meant...

    ...just gigging ya.

    :D
     
    #27     Feb 21, 2007
  8. Ok, it's what i thought. Let me cancel my application. LOL
     
    #28     Feb 21, 2007
  9. MTE

    MTE

    You should really change the terminology you use! TOS is doing NO estimation of future implied volatility whatsoever, the only one making estimations is you when you change the volatility number on Analyze tab in TOS.
     
    #29     Feb 22, 2007
  10. MTE

    MTE

    I don't know how much time has passed since you looked at their software, but I can tell you that in the last year it has come a long way, so it may still be worth it re-opening that account.:)
     
    #30     Feb 22, 2007