Abstract: This paper investigates asset trade in a general-equilibrium complete-markets endowment economy with heterogeneous agents. It shows that standard no-trade results cease to hold when agents have heterogeneous beliefs and that substantial trade volume is generated, even in the presence of a spanning set of assets. Further, trade volume and price movements have a positive relationship in the model, as is well documented in the empirical literature. This paper also develops a computational algorithm for solving finite-period heterogeneous-beliefs economies and demonstrates how the problem is well suited for large-scale parallel computing methods, such as GPU computing.