We provide two new closed-form approximation methods for pricing spread options on a basket of risky assets: the extended Kirk approximation and the second-order boundary approximation. The latter method generalizes the results in Li et al. [J. Deriv., 2008, 15, 58-80] to spread options on an...

A new successive over-relaxation method to compute the Black-Scholes implied volatility is introduced. Properties of the new method are fully analysed, including global well-definedness, local convergence, as well as global convergence. Quadratic order of convergence is achieved by either a...