Title
Computing deltas without derivatives.
Abstract
A well-known application of Malliavin calculus in mathematical finance is the probabilistic representation of option price sensitivities, the so-called Greeks, as expectation functionals that do not involve the derivative of the payoff function. This allows numerically tractable computation of the Greeks even for discontinuous payoff functions. However, while the payoff function is allowed to be irregular, the coefficients of the underlying diffusion are required to be smooth in the existing literature, which for example already excludes simple regime-switching diffusion models. The aim of this article is to generalise this application of Malliavin calculus to Itô diffusions with irregular drift coefficients, where we focus here on the computation of the delta, which is the option price sensitivity with respect to the initial value of the underlying. To this end, we first show existence, Malliavin differentiability and (Sobolev) differentiability in the initial condition for strong solutions of Itô diffusions with drift coefficients that can be decomposed into the sum of a bounded, but merely measurable, and a Lipschitz part. Furthermore, we give explicit expressions for the corresponding Malliavin and Sobolev derivatives in terms of the local time of the diffusion, respectively. We then turn to the main objective of this article and analyse the existence and probabilistic representation of the corresponding deltas for European and path-dependent options. We conclude with a small simulation study of several regime-switching examples.
Year
DOI
Venue
2017
10.1007/s00780-016-0321-3
Finance and Stochastics
Keywords
Field
DocType
Greeks, Delta, Option sensitivities, Malliavin calculus, Bismut–Elworthy–Li formula, Irregular diffusion coefficients, Strong solutions of stochastic differential equations, Relative L2$L^{2}$-compactness, 60H10, 60H07, 60H30, 91G60, C02, C63
Financial economics,Mathematical optimization,Mathematical finance,Sobolev space,Differentiable function,Malliavin calculus,Initial value problem,Lipschitz continuity,Malliavin derivative,Mathematics,H-derivative
Journal
Volume
Issue
ISSN
21
2
1432-1122
Citations 
PageRank 
References 
2
0.49
2
Authors
4
Name
Order
Citations
PageRank
D. Baños120.49
Thilo Meyer-Brandis242.02
Frank Proske3122.54
S. Duedahl420.49