This paper estimates an Heterogeneous Agent Model (HAM) on currency trader indices to explain the large shifts in profitability in currency styles surrounding the global financial crisis. In the model, fund managers allocate capital conditional on recent performance to a value strategy, a momentum strategy, and a carry strategy. Subsequent estimation results reveal that (1) a large part of the behavior of currency managers can indeed be described by these three simple strategies, and (2) currency managers shift capital from recent winning styles to recent losing styles, and hence apply a negative feedback strategy. We finally show that a negative feedback strategy is indeed optimal, but currency managers could improve performance by applying it less aggressively if they were able to. © 2013 Copyright Taylor and Francis Group, LLC.