• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/51

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

51 Cards in this Set

  • Front
  • Back

Monte Carlo Valuation - Simulating Standard Normal Variables




z =


Monte Carlo Valuation - Simulating Standard Normal Variables




zi =

Monte Carlo Valuation - Simulating Lognormal Stock Prices




Not interested in the intermediate prices:


ST =

Monte Carlo Valuation - Simulating Lognormal Stock Prices




Interested in the intermediate prices:


St+h = ...


ST =

Monte Carlo Valuation - Risk neutral vs. True

- Use the risk-neutral dist only when discounting is needed. Pricing options.


- Use the true dist when discounting is not needed. True exp payoff & prob.

Monte Carlo Valuation - Control Variate Method




A.K.A

Boyle Modification

Monte Carlo Valuation - Control Variate Method




Y* =

Monte Carlo Valuation - Control Variate Method




Y* =


Y bar =


X =


X bar =

where


Y* = control variate est for option Y


Y bar = Monte Carlo est for Option Y


X = Exact/True price of Option X


X bar = Monte Carlo est for Option X

Monte Carlo Valuation - Control Variate Method




Var[Y*] =

Monte Carlo Valuation - Control Variate Method




Var[Y*] is minimized when:




beta =

The bottom Var[X bar] is the control variate.

Monte Carlo Valuation - Control Variate Method




When beta is set to minimize Var[Y*]:




Var[Y*] =


Monte Carlo Valuation - Antithetic Variate Method




For every ui, also simulate using ...

1 - ui

Uniform

Monte Carlo Valuation - Antithetic Variate Method




For every zi, also simulate using ...

-zi


Standard normal

Monte Carlo Valuation - Stratified Sampling




Define

Break the sampling space into equal size spaces. Then, scale the uniform numbers into equal size spaces.

Brownian Motion




Z(t): Pure/Standard Brownian Motion 4 Characteristics:

1. Z(0) = 0

2. Z(t+s) - Z(t) ~ N(0,s) Normal dist.


Z(t) - Z(0) ~ N(0,t)


3. Z(t+h) - Z(t) is independent of Z(t) - Z(t-s)


4. Z(t) is continuous

Brownian Motion Z(t) is a martingale if

* E[ Z(t+h) - Z(t) ] = 0*E[ Z(t+h) | Z(t) ] = Z(t)

Brownian Motion Properties:

1. Quadratic variation = T


2. Cubic or higher order variation = 0


3. Total variation = ∞

Arithmetic Brownian Motion




dX(t) =

a dt + b dZ(t)

Arithmetic Brownian Motion




X(T) - X(0) =

~aT + bZ(t)

Arithmetic Brownian Motion




X(t) - X(0) ~

N(at,b^2t)

Ornstein-Uhlenbeck Process




dX(t) =

λ[α - X(t)]dt + σdZ(t)

Geometric Brownian Motion




dX(t) =

a X(t) dt + b X(t) dZ(t)

Geometric Brownian Motion




dX(t) / X(t) =

a dt + b dZ(t)

Geometric Brownian Motiond




d[ ln X(t) ] =

(a - 0.5b^2) dt + b dZ(t)

Geometric Brownian Motion




X(t) =

X(0) e ^[(a - 0.5b^2) t + b dZ(t)]

Geometric Brownian Motion




ln[ X(t) / X(0) ] ~ N[ m = ... , v^2 = ... ]

~ N[ m = (a-0.5b^2)t, v^2 = tb^2]

Geometric Brownian Motion - The followings are equivalent:


* The Black-Scholes framework ...


* dS(t) = ...


* dS(t) / S(t) = ...


* d [ln S(t) ] = ...


* S(t) = ...


* ln[ S(t) / S(0) ] ~ N[m=..., v^2=...]

* The Black-Scholes framework applies.


* dS(t) = (α-δ) S(t) dt + σ S(t) dZ(t)


* dS(t) / S(t) = (α-δ) dt + σ dZ(t)


* d [ln S(t) ] = (α-δ-0.5σ^2) d(t) +σ dZ(t)


* S(t) = S(0) e^[(α-δ-0.5σ^2)t + σZ(t)]


* ln[ S(t) / S(0) ] ~ N[m=(α-δ-0.5σ^2)t, v^2=tσ^2]

Ito's Lemma




dV =

Vs dS + 0.5Vss (dS)^2 + Vt dt

Multiplication Rules




dt * dt =


dt * dZ = dZ * dt =


dZ * dZ =

dt * dt = 0


dt * dZ = dZ * dt = 0


dZ * dZ = dt

Sharpe Ratio




Φ =

Φ = (α-r) / σ


Two Ito's processes depending on the same dZ(t) will have equal Sharpe ratios.

Risk-free Portfolio - For a portfolio consisting of Asset 1 and Asset 2:




Return on Asset 1 =

dS1 + δ1 S1 dt

Risk-free Portfolio - For a portfolio consisting of Asset 1 and Asset 2:




Return on Asset 2 =

dS2 + δ2 S2 dt

Risk-free Portfolio - For a portfolio consisting of Asset 1 and Asset 2:




Total return on the portfolio =

N1 (dS1 + δ1 S1 dt ) + N2 ( dS2 + δ2 S2 dt ) +

Risk-free Portfolio


The coefficient of dZ =


Risk-free --> The coefficient of dZ =

= N1 [ σ1 S1 ] + N2 [ σ2 S2 ]

= 0, risk-free

Risk-free Portfolio




N1 =


N2 =



Risk-neutral Pricing




dS(t) / S(t) =


α or r



Risk-neutral Pricing

Risk-neutral Pricing





Risk-neutral Pricing

Risk-neutral Pricing



Risk-neutral Pricing




True Measure vs. Risk-neutral Measure



Proportional Portfolio


x:


1-x:

x: percentage invested in Asset A


1-x: percentage invested in Asset B

Proportional Portfolio


W(t):

value of the portfolio at time t

Proportional Portfolio




dW(t) / W(t) + δw dt =



Proportional Portfolio




If Asset A is a risk-free asset, then:


dA(t) / A(t) + δA dt =


so dW(t) / W(t) + δw dt =

= r dt




= x[r dt] + (1-x)[...] see previous slide.

The Black-Scholes Equation


δ:


δ*:

δ: dividend yield on stock


δ*: dividend yield on derivative/claim/security

The Black-Scholes Equation


with Vs, Vss, Vt



The Black-Scholes Equation


with Greeks



S^a (Ito Process)


E[S(T)^a] =



S^a


Ft,T[S(T)^a] =


S^a


δ* =

r - a(r-δ) - 0.5a(a-1)σ^2

S^a


Gamma γ =

a(α-r) + r


Total return rate

S^a


dS^a / S^a =

[a(α-δ) + 0.5a(a-1)σ^2] dt + aσ dZ(t)