The trading behavior in a market is often backed by asymmetric information, making the market a asymmetric game. Albert S. Kyle proposed a micro-structure formulation in 1985, stating that such market consists of three players: an insider, a random noise trader, and a market maker. His successors also proved that there exist an equilibrium with additional conditions. In this post, we will discuss the formulation of Kyle's model formulated as an extensive form game and an Optimal-Transport based setting of equilibrium.