I present a fully-rational symmetric-information model of an IPO, and a dynamic imperfectly competitive model of trading in the IPO aftermarket. The model helps to explain IPO underpricing, underperformance, and why share allocations favor large institutional investors. In the model, underwriters need to sell a fixed number of shares at the IPO or in the aftermarket. To maximize revenue and avo...

We employ a model of leverage-induced explosive behavior in financial markets to develop a measure of financial market instability. Specifically, we derive a quantitative condition for how large levered investors can become relative to the whole market before the demand curve for securities suddenly becomes upward-sloping and small price declines cascade as levered investors are forced to liqui...

For over 30 years academics and practitioners have been debating the merits of the CAPM. One of the characteristics of this model is that it measures risk by beta, which follows from an equilibrium in which investors display mean-variance behavior. In that framework, risk is assessed by the variance of returns, a questionable and restrictive measure of risk. The semivariance of returns is a mor...

Theoretical models predict that overconfident investors will trade more than rational investors. We directly test this hypothesis by correlating individual overconfidence scores with several measures of trading volume of individual investors (number of trades, turnover). Approximately 3000 online broker investors were asked to answer an internet questionnaire which was designed to measure vario...

In this paper we seek to explain the behavior of the long term interest rate in the U.S. over the last 50 years using the idea that investors had only limited information about the process generating short term interest rates. Investors are assumed to behave according to the expectations hypothesis of the term structure but use econometric methods to learn about the appropriate model for short ...

This study examined the role of positive and negative discretionary accrual management in the stock price impact. A sample of 66 firms listed in Tehran Stock Exchange was selected for a ten-year period (2008-2017). Accrual management was found to lead to significant changes in stock prices, and uninformed investors incur trading costs caused by the stock price impact. The results showed two key...

Our study analyzes the determinants of investors’ risk taking behavior. We find that investors’ risk taking behavior is affected by their subjective risk attitude in the financial domain and by the risk and return of an investment alternative. Our results also suggest that, consistent with previous findings in the literature, objective or historical return and volatility of a stock are not as g...