  We study optimal trading in an Almgren-Chriss model with running and terminal
inventory costs and general predictive signals about price changes. As a
special case, this allows to treat optimal liquidation in "target zone models":
asset prices with a reflecting boundary enforced by regulatory interventions.
In this case, the optimal liquidation rate is the "theta" of a lookback option,
leading to explicit formulas for Bachelier or Black-Scholes dynamics.
