"Trading as a Business" quant interview, highly recommended

Discussion in 'Trading' started by HiddenAgenda, Nov 18, 2009.

  1. pedro01

    pedro01

    If you use Black-Scholes to price options and then make adjustments for the prices you don't like - then you are not using Black-Scholes.

    To illustrate the point, let's work on a fictional concept we shall call "FPM" - or "Fair Penis Measurement".

    Let's say I produce my FPM by following the strict rules. Take a calibrated ruler, place it at the base of my penis and then take a reading at the furthest point my penis reaches along the ruler to produce a measurement of 10.5 inches. That gives me an FPM of 10.5

    Then let's say another fellow, yourself for instance, does the same thing. You aren't happy with the measurement of 3.5 inches, so you decide to break off the first 5 inches of the ruler and start again. You now give yourself an FPM of 8.5.

    In this case, although we followed a similar process, you did not adhere to the rules of FPM and therefore your FPM of 8.5 is invalid.

    Similarly - increasing the volatility input that goes into Black Scholes on the outlying options to produce a more acceptable output is not using Black Scholes at all which requires the same volatility input to calculate all strike prices.

    Now - call me a fool again... :)
     
    #71     Nov 20, 2009
  2. pedro01

    pedro01

    I think we can safely say that quants should not be used to help create and maintain models to price derivatives.

    We can say that based on the real life experience and the outcomes of people relying on their models.

    If you maintain that this is all quants do (and I do not agree with that), then shouldn't we just get rid of them altogether ?
     
    #72     Nov 20, 2009
  3. But, pedro, this just tells me that you don't appreciate how scientific method works...

    The fact that a particular theory has been shown to not work in certain settings doesn't mean that it has no merit. It certainly doesn't mean that its authors don't deserve their accolades. Or do you think Newton, Maxwell and Darwin, for example, should all be forgotten? Should we consider their contribution to science null and void, just because modern science has moved on?

    The point is that seminal theories, like Black-Scholes, are stepping stones. They may be flawed in a whole variety of ways, but they advance our understanding of the world and allow others to build upon them.

    As to the blame, you'd have to be more specific. I certainly don't see how anyone could blame Black-Scholes for anything. Everyone and their mother knows about the various flaws of B-S, which is precisely why so many next-generation models have been developed. Who else would you like to blame? David Li, whose name I hear mentioned a lot?
     
    #73     Nov 20, 2009
  4. pedro01

    pedro01

    Actually, I understand how science works.

    I understand that science could not come up with a masterpiece like Da Vinci.

    I understand that a Physics Phd couldn't run a fruit and vegetable stall like a 50 year old cockey 'barrow boy'.

    I understand that neither a biologist or chemist could have created the peach flambe.

    I understand that financial academics got frustrated at following the world of finance and so created the myth that the markets were a problem with mathematical solutions so that academia could be seen to lead the world of finance.

    So far, this has failed.

    Finance is not a science.

    In physics, academia will lead the way. In art, fashion and finance they will lag
     
    #74     Nov 20, 2009
  5. Well, we'll have to disagree on this then, rather than continue this discussion ad infinitum.
     
    #75     Nov 20, 2009
  6. pedro01

    pedro01

    I agree :D

    Good discussion though.
     
    #76     Nov 20, 2009
  7. The SHOCKING news is that the solution often lies in the area of criminal law, not exact sciences :D

    Check this out, a research piece by a hedge fund due diligence firm:

    http://www.castlehallalternatives.com/upload/publications/2507_ManhattantoMadoffPaper.pdf

    It turns out that the single most widespread reason for hedge fund failures (failures for investors, not for the founders :D) is theft and fraud. It is NOT failure of science.

    Keep things simple. It works.
     
    #77     Nov 20, 2009
  8. A friend of mine has a Ph.D. in Sociolinguistic Analysis.

    I showed him your message, he says you sound like a loser at the bottom of the social ladder.
     
    #78     Nov 20, 2009
  9. lol, and what do economists exactly have to say? And who listens to them? People can say all kinds of crap. Fact remains that large speculative trading positions are taken by humans who are 100% and fully aware of the underlying risk. They took the risk because they knew that they wont be held accountable if the position goes south. I still dont understand where in this equation you guys try to squeeze in economists, quants, math, and whatever formulae you wanna pick...


     
    #79     Nov 20, 2009
  10. lol, I seriously suggest you stick to software development, you clearly never seriously traded options or made markets in options. Case rest!

    P.S.: People referencing to penis size generally have issues regarding the same, did not know that?



     
    #80     Nov 20, 2009