In this article, we present a flexible approach to the valuation of Parisian and similar exotic options. The approach is based on the numerical solution of a fundamental partial differential equation and can easily accommodate variations like American early exercise features, different payoff...

In this paper we model the value of a firm based on its current earnings and cash balances. The value is modelled on the assumption that earnings follow a mean-reverting process. The effect of advertising on earnings is modelled, and the condition for optimal advertising derived. The value of...

We derive a nonlinear parabolic partial differential equation for the value of portfolios of options in the presence of proportional transaction costs. This assumes a Leland world of transacting after each time interval, which is of fixed length. The equation reduces to the modified variance...

The subject matter of this paper concerns the natural price barriers that markets encounter. The ideas in this paper can be applied to any market: equity, commodity, currency or fixed income. It is common market experience that prices (or yields) exhibit resistance and support: at key levels...

We explain the ideas behind the valuation of options with early exercise features, so called American options. We also aim to clarify some popular misconceptions about when an American option should be exercised. These misconceptions seem to be prevalent among both academics and practitioners.

We show how to use 'uncertainty' in place of the more traditional Brownian 'randomness' to model a short-term interest rate. The advantage of this model is principally that it is difficult to show statistically that it is wrong. Whether the model is useful for pricing fixed-income products is...

Two of the authors (DE and PW) recently introduced a non-probabilistic spot interest rate model. The key concepts in this model are the non-diffusive nature of the spot rate process and the uncertainty in the parameters. The model assumes the worst possible outcome for the spot rate path when...