50 Matching Annotations
  1. Dec 2024
    1. timate for the stock price as the dicsounted expected value of the terminal stock price

      Should be \(S_t(m,i)\) we should also explain m here. The mth subdivision?

    2. we would generate a standard normal Zi and compute log⁡Si(T)=log⁡S(0)+(r−q−12σ2)T+σTZi,log⁡Si′(T)=log⁡S(0)+(r−q−12σ2)T−σTZi. Given the first terminal price, the value of the derivative will be some number xi and given the second it will be some number yi. The date–0 value of the derivative is estimated as

      Why does \(\log S_i(T)\) have the same randomness as \(\log S_i^{'}(T)\)? Do we need \(Z_i^{'}\) for the second simulated price?

      also it might help to write \(x(S_i(T)) \) and \(y(S_i^{'}(T)) \) in the mean estimation for clarity.

    3. The black scholes fromula= 4.759422392871532

      We've already the Black-Scholes function. Based on how compile.py works, we should be able to just recall it from the previous section and use it in the above block.

    4. cp

      these variables are confusing. We should be more explicit about what these mean (e.g., cp to call_price and cc,cc1 to call_payoff_1, call_payoff_2)

  2. Nov 2024
    1. where now B∗ denotes a Brownian motion when V is the numeraire. This is equivalent to

      @Mark they should know Girsonov Thm before this point

    2. Close observation of the right hand side we see this is the drift term of Ito expansion for C if we work in the risk neutral measure.

      what is 'this' referring to?

    3. on the volatility coefficients and on B and B∗ to distinguish the Brownian motion driving S from the Brownian motion driving Y and to distinguish their volatilities are not needed here

      this is grammatically confusing

    1. The code below simulates n=10000 paths with m=1000 time steps. There are some features of the simulation which will prove useful late

      before we used m as the number of paths. Inconsistency here @mark

    2. ts, to a deterministic model, for example, in a model predicting the position of a falling object.

      The model of noise was developed by Ito to account for random disturbances to a deterministic model, such as unpredictable wind gusts in predicting the position of a falling object.

    1. The expected future (date–T) value equals the current (date–0) value, so the random variables (C/R and S/R or C/S and R/S) are

      are martingales?