The Vol. 5 No. 2 Issue of the Numerix Journal spotlights theoretical aspects of current and upcoming Numerix features. It begins with a discussion of MVA and Initial Margin requirements, and next looks at the Numerix implementation of the FX Joint Heston model. The issue also examines probability distributions of barrier hitting times, and includes a white paper on European swaption pricing methodology for the Hull-White two-factor model. Finally, the issue highlights Numerix’s implementation of an arbitrage-free volatility surface using a linear programming formulation.