Traditional market makers are losing their importance as automated systems have largely assumed the role of liquidity provision in markets. We update the model of Glosten and Milgrom (1985) to analyze this new world: we add multiple securities and introduce an automated market maker who prices...

With the demise of traditional market makers and proliferation of trade execution algorithms that mix market and limit orders, it is no longer clear who provides liquidity in limit order book markets and what determines their liquidity provision decisions. To examine these issues, we develop and...