Weak approximation of stochastic differential equations and application to derivative pricing
Syoiti Ninomiya, Nicolas Victoir
TL;DR
The paper tackles efficient weak approximation of expectations E[f(Y(1,x))] for SDEs by introducing a second-order weak scheme that uses Bernoulli-Gaussian randomization to drive step updates. It proves the new method achieves an error bound of |E[f(X^{New,n}_1)] − E[f(Y(1,x))]| ≤ C_f/n^2 and demonstrates substantial practical gains when combined with quasi-Monte Carlo for pricing Asian options under the Heston stochastic volatility model. The approach preserves stability and general applicability, avoiding negative volatility issues that can plague Euler-based schemes and enabling fast, high-accuracy derivative pricing. Overall, the combination of a simple, robust 2nd-order weak scheme with QMC yields dramatic speedups over traditional Euler-based methods for high-dimensional, diffusion-driven pricing problems.
Abstract
The authors present a new simple algorithm to approximate weakly stochastic differential equations in the spirit of [1] and [2]. They apply it to the problem of pricing Asian options under the Heston stochastic volatility model, and compare it with other known methods. It is shown that the combination of the suggested algorithm and quasi-Monte Carlo methods makes computations extremely fast. [1] Shigeo Kusuoka, ``Approximation of Expectation of Diffusion Process and Mathematical Finance,'' Advanced Studies in Pure Mathematics, Proceedings of Final Taniguchi Symposium, Nara 1998 (T. Sunada, ed.), vol. 31 2001, pp. 147--165. [2] Terry Lyons and Nicolas Victoir, ``Cubature on Wiener Space,'' Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences 460 (2004), pp. 169--198.
