Most market places in today's exchange industry operate on fully electronic trading systems. The predominant form of trading systems is the open limit order book pooling all buy and sell limit orders in one single order book. The attractiveness of an order book is determined by its liquidity. Consequently, liquidity is the competitive factor for an exchange. However, it is not the exchange that provides the liquidity but the limit orders standing in the order book. The question is: Who are these traders that provide liquidity on a voluntary basis?

A high frequency transaction data set for the German equity market is the basis for Alexandra Hachmeister's extensive empirical analysis. This includes a detailed market description of the German equity market, a new methodological approach for the identification of informed traders and finally the analysis of the individual liquidity providing and demanding behavior of the identified informed traders. Questioning the existing theoretical literature on liquidity provision in equity markets, she finds strong evidence for liquidity providing behavior of informed traders.

Autorentext
Dr. Alexandra Hachmeister promovierte bei Prof. Dr. Dirk Schiereck am Stiftungslehrstuhl Bank- und Finanzmanagement der European Business School, Oestrich-Winkel. Sie ist derzeit als Mitarbeiterin der Deutsche Börse AG tätig.

Zusammenfassung
Today, the majority of large international stock exchanges operates electronic trading systems and abandons more and more floor trading which relies upon specialists and market makers. The preferred trading mechanism is the so-called open limit order book, which induces continuous double auction trading without any market participants designated to facilitate trading through their own trading activity. Trading in these market structures is considered the more attractive the smaller the spread between the highest buy and the lowest sell limit order, i.e. the more liquid a market is. This leads to the question which market participants are willing to enter buy and sell limit orders in the open limit order book to enable liquid trading. Traditional theoretical literature concludes that exclusively uninformed traders enter limit orders and provide liquidity while impatient informed traders enter liquidity-consuming market orders. Recent, primarily experimental studies question this rigid distinction. This is the starting point for Ms Hachmeister's thesis, when she analyzes based upon an individually compiled extensive set of transaction data informed traders' order type choice.

Inhalt
Institutional Set-up and Academic Framework.- Institutional Setting.- Liquidity.- Informed Trading.- Informed Trading and Liquidity.- Empirical Analyses.- Research Design.- Market Description: Liquidity and Informed Trading.- Trader Classification.- Liquidity Demand and Supply Behavior of Informed Traders.- Résumé.