Incorporating Linear Neutrality Constraints into the Garleanu-Pedersen Framework for Dynamic Trading

In an elegant and influential paper, Garleanu and Pedersen derive the optimal dynamic trading policy assuming quadratic transaction costs and assets with predictable, mean-reverting returns. We show that their approach can be extended to incorporate linear neutrality constraints, such as dollar and beta neutrality, which are of practical interest. The solutions remain analytically tractable and are closely related to those of the unconstrained policy.