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5
votes
2answers
88 views

Is the money market account (MMA) numeraire and the forward measure equivalent?

Suppose we have a risk-neutral measure $\tilde{\mathbb{P}}$. The money market account is given as $M(t) = e^{\int^t_0 R(s) ds}$, while the price of the zero-coupon bond at time $t$ that matures at $T$ ...
3
votes
2answers
32 views

The relation between exchange rate SDE and respective interest rates

The exchange rate between a domestic currency money market and a foreign currency money market can be expressed as $$ dQ(t) = (r_d - r_f)Q(t)dt + \sigma Q(t)d\tilde{W}(t) $$ where $r_d$ is the ...
4
votes
1answer
77 views

Deriving Black Scholes PDE under stock as a numeraire

There are many ways to derive the Black Scholes PDE. The Martingale way would be to demand the option price is driftless according to particular measures. Below I derive the correct PDE using the bank ...
0
votes
1answer
19 views

libor rate - local martingale

I am a newbie for Libor rates and all these questions... Let be : $L(t,\delta)$ the Libor rate and $L_{t}(T,\delta)$ the forward Libor rate. Let's define : $Lb(T,\delta):=1+\delta ...
0
votes
0answers
21 views

Effect on variance of change of measure

My current understanding: (a) changing the probability measure of a diffusion process does not change the variance. (b) for a general stochastic process the variance may change. Please confirm whether ...
2
votes
0answers
29 views

Expectation of expression with two currencies under forward measure

I'm trying to calculate the expected value, at time $0$, of a cashflow paid at time $T$, resetting at time $t$. The coupon is of the form: ...
1
vote
1answer
39 views

Is the delta of a call option a martingale using the stock numeraire?

For example in the Black_scholes case the delta N(d1) does appear to be equal to the expectation (under the stock measure) of the delta at expiration, which is the expectation of I(S(T)>K). Is ...
5
votes
1answer
320 views

How to use a change of numeraire to price this option?

I recently asked this question regarding how to price an option with payoff: $$\text{Payoff}_T = (A_TR_T - A_T \lambda)^+ $$ Let's assume for generality that $A_t$ and $R_t$ are GMB's: $$dA_t = ...
2
votes
2answers
158 views

Option with payoff $K^2/S^2$

Given the dynamics of the risky asset ( with dividend $q$ ), $$ \frac{dS_t}{S_t}=(\mu-q)dt + \sigma dW_t^P $$ Consider a european option with payoff, $$ P_0(S) = \begin{cases} 1, & ...
4
votes
4answers
430 views

Understanding $N(d_1)$ and how to use the stock itself as the numeraire?

Assume the stock price follows a geometric Brownian motion Then in Black-Scholes pricing model, $N(d_2)$ is the risk-neutral probability that the option expires in-the-money. However, it is said that ...
4
votes
1answer
171 views

Change of numeraire and reference asset

Learning about change of numeraire, and came across this statement: The price of any asset divided by a reference asset (called numeraire) is a martingale (no drift) under the measure associated ...
1
vote
0answers
72 views

Value of an option to exchange an asset for another

I'm working out the examples in the paper "Changes of Numeraire, Changes of Probability Measure and Option Pricing", corollary 3. An option of exchanging asset 2 against asset 1 at time T, its time-0 ...
3
votes
2answers
281 views

Libor Market Model: numeraire change

I am currently studying the Libor forward market model, and although I get the mechanics behind the main arguments, I still do not have an intuitive idea of what's exactly the objective behind ...
2
votes
2answers
576 views

How to use the stock as a numeraire to price a derivative with payoff of the form $(S_T f(S_T))^+$?

I have $\frac{dS_t}{S_t} = rdt + \sigma dW_t$ as usual under the money-market numéraire and I need to price options with payoffs $$(S_T f(S_T))^+$$ How do I express the stock dynamics using the ...
3
votes
1answer
255 views

Numéraire — couldn't understand the wiki explanation

I'm trying to understand Numéraire concept so am reading the wiki page: I couldn't understand the last formula's 2nd equation: $$ ...
1
vote
1answer
1k views

Baye's rule for conditional expectations (Proof review)

The Baye's rule for conditional expectations states $$ E^Q[X|\mathcal{F}]E^P[f|\mathcal{F}]=E^P[Xf|\mathcal{F}] $$ With $f=dQ/dP$ - thus being the Radon-Nikodyn derivative and $X$ being ...
7
votes
2answers
818 views

T-Forward Price on risk-neutral measure

i have and question concerning the T-forward price definition on the Robert J.Elliot's book : Mathematics of Financial Markets. On his chapter 9, definition 9.1.3 p.249. He give the formula without ...