The standard hypothesis concerning the behavior of asset returns states that they follow a random walk in discrete time or a Brownian motion in continuous time. The Brownian motion process is characterized by a quantity, called the Hurst exponent, which is related to some fractal aspects of the...

A contingent claims valuation model which allows to highlight the implications of program trading in spot markets for the pricing of European-style foreign currency options and for the volatility strike structure implicit in these contracts is devoloped. The curvature of the volatility strike...