Structural changes, bid-ask spread composition and tick size in inter-bank futures trading

This paper studies a period containing three major structural changes, which constitute a natural experiment in the NYSE.Euronext-LIFFE European short-term interest rate (STIR) futures market. These changes comprise (1) a 50% reduction in minimum tick size for the most heavily traded contract, (2) European Monetary Union and (3) the transition from open outcry to electronic trading. We analyse a number of microstructure features of the four largest European interest rate futures contracts throughout this period. In particular, we focus on bid–ask spread composition using a recent model which is appropriate for this market structure. Our analysis identifies the tick size as the largest bid–ask spread component in almost every instance, which suggests that participants in this STIR future market might benefit from a reduction in minimum tick sizes