Imbalance attractors for a strategic model of market microstructure

Abstract

In this paper we extend the series of our studies on the properties of an interacting particle model for market microstructure. In our earlier work we defined a Markov process on the majority opinion of the agents, obtained the transition probabilities and analyzed the martingale properties of the ensuing wealth process. Here we relax the assumption on the choices of individual agents by allowing mixed strategies, offering opportunities for the agents to gain intermediate submartingale exposure for their individual wealth processes. We develop a novel two-dimensional spin system to model the critical regions of the wealth process as a reflection of the agents' behaviors. We exhibit strategic conflicts between individual market participants and the market as a whole, and identify a new source of uncertainty arising from `reinforced expectations'.