Microstructure and Execution Strategies in the Global Spot FX Market

Modern global inter-bank spot foreign exchange is essentially a limit-order market. Execution strategies in such a market may differ from those in markets that permit market orders. Here we describe microstructure and dynamics of the EBS market (EBS being an ICAP company is the leading institutional spot FX electronic brokerage). In order to illustrate specifics of the limit-order market, we discuss two problems. First, we describe our simulations of maker loss in case when the EUR/USD maker order is pegged to the market best price. We show that the expected maker loss is lower than the typical bid/offer spread. Second, we discuss the problem of optimal slicing of large orders for minimizing execution costs. We start with analysis of the expected execution times for the EUR/USD orders submitted at varying market depth. Then we introduce a loss function that accounts for the market volatility risk and the order's P/L in respect to the market best price. This loss function can be optimized for given risk aversion. Finally, we apply this approach to slicing large limit orders.