Portfolio rebalancing trades off tracking error against the transaction costs associated
with avoiding tracking error. Prior analytical work derived optimal rebalancing strategies
that minimize the expected transaction costs required to achieve a given level of tracking
error. Using these strategies results in the same level of tracking error as naive
strategies often observed in practice but with much lower transaction costs. Additional
(substantial) reductions in expected transaction costs can be obtained by using
derivatives to synthetically rebalance a portfolio. The design of an
efficient synthetic rebalancing program, however, is complicated. This article describes
the key elements in such a complex design.