Abstract. Partial integro-differential equation (PIDE) formulations are often preferable for pricing options under models with stochastic volatility and jumps, especially for American-style option contracts. We consider the pricing of options under such models, namely the Bates model and the so-called stochastic volatility with contemporaneous jumps (SVCJ) model. The nonlocality of the jump terms in these models leads to matrices with full matrix blocks. Standard discretization methods are not viable directly since they would require the inversion of such a matrix. Instead, we adopt a two-step implicit-explicit (IMEX) time discretization scheme, the IMEX-CNAB scheme, where the jump term is treated explicitly using the second-order Adams-Bashforth (AB) method, while the rest is treated implicitly using the Crank-Nicolson (CN) method. The resulting linear systems can then be solved directly by employing LU decomposition. Alternatively, the systems can be iterated under a scalable algebraic multigrid (AMG) method. For pricing American options, LU decomposition is employed with an operator splitting method for the early exercise constraint or, alternatively, a projected AMG method can be used to solve the resulting linear complementarity problems. We price European and American options in numerical experiments, which demonstrate the good efficiency of the proposed methods. It is well known that fitting empirically observed option prices into the Black-Scholes model typically implies a volatility distribution with a smile-like shape. This volatility smile becomes more pronounced near the maturity date. The usual modifications of the BlackScholes model to explain such implied volatility patterns include models with jumps and/or stochastic volatility. The underlying asset price can be completely modeled by an infinite activity model such as the Carr-Geman-Madan-Yor (CGMY) model [8]. Over long time intervals the component behaving like the geometric Brownian motion becomes the dominant part in the model. For options with long maturities, the stochastic volatility models, for example the Heston model [24], are often regarded as more appropriate. For options with short maturities, however, jumps become increasingly important as a purely geometric Brownian motion driven process would require extremely high levels of volatility to explain the pronounced volatility smile pattern. Well-known jump-diffusion models in the literature include the Merton [34]