Before revision:  Pricing exotic derivatives often involves Monte Carlo simulations, which rely on stochastic processes to model the underlyings . It is thus critical to choose appropriate models and precisely calibrate them, so that they reflect the market scenario.
After revision:  Pricing exotic derivatives often involves Monte Carlo simulations, which rely on stochastic processes to model the underlyings : it is thus critical to choose appropriate models and precisely calibrate them, so that they reflect the market scenario.