{ "id": "1508.06797", "version": "v1", "published": "2015-08-27T10:50:55.000Z", "updated": "2015-08-27T10:50:55.000Z", "title": "Lie Symmetry Analysis of the Black-Scholes-Merton Model for European Options with Stochastic Volatility", "authors": [ "A. Paliathanasis", "K. Krishnakumar", "K. M. Tamizhmani", "P. G. L. Leach" ], "comment": "14pages, 4 figures", "categories": [ "math.AP", "q-fin.PR" ], "abstract": "We perform a classification of the Lie point symmetries for the Black-Scholes-Merton model for European options with stochastic volatility $% \\sigma$, in which the last is defined by a stochastic differential equation with the Orstein-Uhlenbeck term. In this model the value of the option is given by a linear (1+2) evolution partial differential equation, in which the price of the option depends on two independent variables, the value of the underlying asset $S$ and a new variable, $y$, which follow from the Orstein-Uhlenbeck process. We find that for arbitrary functional form of the volatility, $\\sigma(y)$, the (1+2) evolution equation admits always two Lie symmetries, plus the linear symmetry and the infinity number of solution symmetries. However when $\\sigma(y)=\\sigma_{0}$ and since the price of the option depends on the second Brownian motion in which the volatility is defined, the (1+2) evolution is not reduced to the Black-Scholes-Merton equation, the model admits five Lie symmetries, plus the linear symmetry and the infinity number of solution symmetries. Furthermore we apply the zero-order invariants of the Lie symmetries and we reduce the (1+2) evolution equation to a linear second-order ordinary differential equation. Finally we study two models of special interest, the Heston model and the Stein-Stein model.", "revisions": [ { "version": "v1", "updated": "2015-08-27T10:50:55.000Z" } ], "analyses": { "subjects": [ "22E60", "35Q91" ], "keywords": [ "lie symmetry analysis", "black-scholes-merton model", "european options", "stochastic volatility", "linear second-order ordinary differential equation" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }