Price, Trade Size, and Information Revelation in Multi-Period Securities Markets

We study price formation in securities markets, using the sequential trade framework of Glosten and Milgrom [7]. This paper makes one basic methodological advance over previous research on sequential securities trading: we allow traders to choose from n trade sizes in a multi-period market, where n can be arbitrarily large. We examine how trade size multiplicity affects the intertemporal dynamics of trading strategies, bid-ask spreads, and information revelation We show that price impact, as a function of trade size, is increasing and exhibits (discrete) concavity.