A front page Sunday New York Times article on a potential development of new drugs to cure cancer caused the price of EntreMed (ENMD) stock to rise from 12.063 at the Friday close, to open at 85 and close near 52 on Monday. Trading volume was more than 400 times the normal trading volume, and...

The preferred risk habitat hypothesis, introduced here, is that individual investors select stocks whose volatilities are commensurate with their risk aversion. The data, 1995-2000 holdings of over 20,000 clients at a large German broker, are consistent with the predictions of the hypothesis:...

A liquidity trader wishes to trade a fixed number of shares within a certain time horizon and to minimize the mean and variance of the costs of trading. Explicit formulas for the optimal trading strategies show that risk-averse liquidity traders reduce their order sizes over time and execute a...

The preferred risk habitat hypothesis, introduced here, is that individual investors select stocks whose volatilities are commensurate with their risk aversion. The data, 1995-2000 holdings of over 20,000 clients at a large German broker, are consistent with the predictions of the hypothesis:...

In an environment where trading volume affects security prices and where prices are uncertain when trades are submitted, quasi-arbitrage is the availability of a series of trades which generate infinite expected profits with an infinite Sharpe ratio. We show that when the price impact of trades...

Retail clients at a major German discount broker trade in tandem - they tend to be on the same side of the market in a given stock during a given day, week, month, and quarter. Neither aggregate liquidity effects nor short sale constraints fully explain this behavior. The systematic execution of...

Although established money managers operate in an environment which seems competitive, they also seem to be very profitable. The present value of the expected future profits from managing a collection of funds is equal to the value of the assets under management multiplied by the profit margin,...

Building on recent developments in behavioral asset pricing, we develop a model in which an increase in the dispersion of investor beliefs under short-selling constraints predicts a bubble, or a rise in a stock's price above its fundamental value. Our model predicts that managers respond to...

Few retail investors actively buy and sell individual stocks. This paper finds that a sample of those who do - over 1,000 customers at a German broker who turn over their portfolio at a median annual rate of 85% - consists of predominantly male, younger, and more educated investors who earn...