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numeraire
Posted: February 4th, 2005, 11:12 am
by DutchQuant
Based on a given numeraire I want to determine the drift of the forward rates in the LMM.Does anyone have a good reference for me?
numeraire
Posted: February 4th, 2005, 2:49 pm
by AlanB
QuoteOriginally posted by: DutchQuantBased on a given numeraire I want to determine the drift of the forward rates in the LMM.Does anyone have a good reference for me?"Interest Rate Models, Theory and Practice", D. Brigo, F. Mercurio"Stochastic Calculus for Finance II, Continuous-Time Models", S. S. Shreve
numeraire
Posted: February 4th, 2005, 3:03 pm
by prettyspecific
if you know the dynamics of the forward rate under the usual martingale measure, then you should be able to compute the explicit dynamics under the new measure a la girsonov. The R-N derivative for the new numeraire should be dP*/dP = N(T)/(N(0)*Beta(T)) where N(t) is the new numeraire. State price density is eta(t) = N(t)/(N(0)*Beta(t)), a martingale under the usual RN measure. d eta(t) = sig.eta.dW. If X(t) is a process with dX = mu_X.dt+sigma_X.dW then mu under the new measure should be mu_X-sigma_X.sig. (At least that's the basic story, as long as there are no complications that it is the *forward* rate you are modelling.) Note that sigma_X is here the diffusion coefficient (I did not assume the diffusuion term was of the form sig.X.dW. Shreve's notes (available on the internet) are a good primer/review.Hope this helps. Maybe you knew all that already.
numeraire
Posted: February 7th, 2005, 8:31 am
by DutchQuant
Thanks,I've been looking around for Shreve's documents and that helps.