This paper studies how the trade size and the historical sequence of trades affect bid-ask spreads, investors’ trading strategies, and the market maker’s learning process in a multi-period economy. First, we show that there is a nonzero cut-off size below which informed traders never buy or...

We study price formation in securities markets, using the sequential trade framework of Glosten and Milgrom. This paper makes one basic methodological advance over previous research on sequential securities trading: we allow for multiple trade sizes for traders to choose from in a multi-period...