The authors develop a dynamic model of market-making incorporating inventory and information effects. The marketmaker is both a dealer and an investor, quoting prices that induce mean reversion in inventory toward targets determined by portfolio considerations. The authors test the model with...

We develop and test a model of intraday price formation based on an explicit description of a representative market maker whose beliefs evolve according to Bayes’ rule. We derive an estimating equation where the weight the market maker places on the order flow as an information signal can be...