629 research outputs found
Exact Simulation of Wishart Multidimensional Stochastic Volatility Model
In this article, we propose an exact simulation method of the Wishart
multidimensional stochastic volatility (WMSV) model, which was recently
introduced by Da Fonseca et al. \cite{DGT08}. Our method is based onanalysis of
the conditional characteristic function of the log-price given volatility
level. In particular, we found an explicit expression for the conditional
characteristic function for the Heston model. We perform numerical experiments
to demonstrate the performance and accuracy of our method. As a result of
numerical experiments, it is shown that our new method is much faster and
reliable than Euler discretization method.Comment: 27 page
A distributed algorithm for European options with nonlinear volatility
A distributed algorithm is developed to solve nonlinear Black-Scholes equations in the hedging of portfolios. The algorithm is based on an approximate inverse Laplace transform and is particularly suitable for problems that do not require detailed knowledge of each intermediate time steps
Applications of Laplace transform for evaluating occupation time options and other derivatives
The present thesis provides an analysis of possible applications of the Laplace Transform (LT) technique to several pricing problems. In Finance this technique has received very little attention and for this reason, in the first chapter we illustrate with several examples why the use of the LT can considerably simplify the pricing problem. Observed that the analytical inversion is very often difficult or requires the computation of very complicated expressions, we illustrate also how the numerical inversion is remarkably easy to understand and perform and can be done with high accuracy and at very low computational cost.
In the second and third chapters we investigate the problem of pricing corridor derivatives, i.e. exotic contracts for which the payoff at maturity depends on the time of permanence of an index inside a band (corridor) or below a given level (hurdle). The index is usually an exchange or interest rate. This kind of bond has evidenced a good popularity in recent years as alternative instruments to common bonds for short term investment and as opportunity for investors believing in stable markets (corridor bonds) or in non appreciating markets (hurdle bonds). In the second chapter, assuming a Geometric Brownian dynamics for the underlying asset and solving the relevant Feynman-Kac equation, we obtain an expression for the Laplace transform of the characteristic function of the occupation time. We then show how to use a multidimensional numerical inversion for obtaining the density function. In the third chapter, we investigate the effect of discrete monitoring on the price of corridor derivatives and, as already observed in the literature for barrier options and for lookback options, we observe substantial differences between discrete and continuous monitoring. The pricing problem with discrete monitoring is based on an appropriate numerical scheme of the system of PDE's.
In the fourth chapter we propose a new approximation for pricing Asian options based on the logarithmic moments of the price average
On accurate and efficient valuation of financial contracts under models with jumps
The aim of this thesis is to develop efficient valuation methods for nancial contracts
under models with jumps and stochastic volatility, and to present their rigorous mathematical underpinning. For efficient risk management, large books of exotic options need
to be priced and hedged under models that are exible enough to describe the observed
option prices at speeds close to real time. To do so, hundreds of vanilla options, which
are quoted in terms of implied volatility, need to be calibrated to market prices quickly
and accurately on a regular basis. With this in mind we develop efficient methods for the
evaluation of (i) vanilla options, (ii) implied volatility and (iii) common path-dependent
options.
Firstly, we derive a new numerical method for the classical problem of pricing vanilla
options quickly in time-changed Brownian motion models. The method is based on ra-
tional function approximations of the Black-Scholes formula. Detailed numerical results
are given for a number of widely used models. In particular, we use the variance-gamma
model, the CGMY model and the Heston model without correlation to illustrate our results. Comparison to the standard fast Fourier option pricing method with respect to
speed appears to favour our newly developed method in the cases considered. Secondly,
we use this method to derive a procedure to compute, for a given set of arbitrage-free
European call option prices, the corresponding Black-Scholes implied volatility surface. In
order to achieve this, rational function approximations of the inverse of the Black-Scholes
formula are used. We are thus able to work out implied volatilities more efficiently than
is possible using other common methods. Error estimates are presented for a wide range
of parameters. Thirdly, we develop a new Monte Carlo variance reduction method to
estimate the expectations of path-dependent functionals, such as first-passage times and
occupation times, under a class of stochastic volatility models with jumps. The method is
based on a recursive approximation of the rst-passage time probabilities and expected oc-
cupation times of Levy bridge processes that relies in part on a randomisation of the time-
parameter. We derive the explicit form of the recursive approximation in the case of bridge
processes corresponding to the class of Levy processes with mixed-exponential jumps, and present a highly accurate numerical realisation. This class includes the linear Brownian
motion, Kou's double-exponential jump-di usion model and the hyper-exponential jump-
difusion model, and it is dense in the class of all Levy processes. We determine the rate
of convergence of the randomisation method and con rm it numerically. Subsequently,
we combine the randomisation method with a continuous Euler-Maruyama scheme to es-
timate path-functionals under stochastic volatility models with jumps. Compared with
standard Monte Carlo methods, we nd that the method is signi cantly more efficient. To
illustrate the efficiency of the method, it is applied to the valuation of range accruals and
barrier options.Open Acces
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