Itô calculus deals with functions of the current state whilst we deal with functions of the current path to acknowledge the fact that often the impact of randomness is cumulative. We express the differential of the functional in terms of adequately defined partial derivatives to obtain an Itô...

The Samp;P 500 index return interacts negatively with its volatility. This paper traces the negative interaction to three distinct economic channels and proposes to disentangle the relative contribution of each channel using Samp;P 500 index options. First, equity volatility increases...

The SABR closed-form formula (Hagan et. al 2002) is the standard for smile-consistent pricing in the swaption market. Here we address the issue of turning SABR assumptions into a consistent and arbitrage-free term structure model in the BGM/Libor Market Model framework. We compute the joint...