Dan Galai

ABSTRACT An individual who chooses to serve as a market‐maker is assumed to optimize his position by setting a bid‐ask spread which maximizes the difference between expected revenues received from liquidity‐motivated traders and expected losses to information‐motivated traders. By characterizing the cost of supplying quotes, as writing a put and a call option to an information‐motivated trader, it is shown that the bid‐ask spread is a positive function of the price level and return variance, a negative function of measures of market activity, depth, and continuity, and negatively correlated with the degree of competition. Thus, the theory of information effects on the bid‐ask spread proposed in this paper is consistent with the empirical literature.

This is the definitive guide to quantifying risk vs. return - fully updated to reveal the newest, most effective innovations in financial risk management since the 2008 financial crisis. Written for risk professionals and non-risk professionals alike, this easy-to-understand guide helps you meet the increasingly insistent demand to make sophisticated assessments of companies' risk exposure. It provides the latest methods for: measuring and transferring credit risk; increasing risk-management transparency; and implementing an organization-wide Enterprise risk Management (ERM) approach. Michel Crouhy is head of research and development at NATIXIS and the founder and president of the NATIXIS Foundation for Quantitative Research. Dan Galai is the Abe Gray Professor of Finance and Business Administration at the School of Business Administration, the Hebrew University in Jerusalem. Robert Mark is the Founding Chief Executive Officer of Black Diamond Risk which provides corporate governance, risk management consulting, risk software tools, and transaction services.