A variety of variables have been used to form contrarian portfolios, ranging from relatively simple measures, like book-to-market, cash flow-to-price, earnings-toprice and past returns, to more sophisticated measures based on the Ohlson model and residual income model (RIM). This paper investigates whether: (i) contrarian strategies based on RIM perform better or worse than those based on the Ohlson model; (ii) contrarian strategies based on more sophisticated valuation models (e.g. Ohlson and RIM) perform much better than the relatively simpler ranking variables that have been used so extensively in the finance literature. Given that the RIM and Ohlson models require greater information inputs and technical know-how, and make different implicit assumptions on future abnormal earnings,it is important to ascertain if they offer significantly greater contrarian profits to outweigh the increased costs that they entail. Indeed, our surprising finding is that simple cash flow-to-price measures appear to do almost as well as the more sophisticated alternatives. One would have expected the sophisticated models to significantly outperform the simple cash flow to price model for the reasons given by Penman (2007).

This paper focuses on insider trading, where the perpetrators exploit market sensitive information to earn profits or avoid losses. The paper's objectives are as follows. First, we seek to examine whether we can detect possible insider trading and stock manipulation and react in almost real time, even though insider trading activity is intended to be evasive. Second, we also estimate the extent of illicit profits (or loss avoidance) that might have been earned. Finally, we analyze, if detection is possible, the appropriate response for regulators and other market participants. We do not restrict our study to cases where corporate events have materialized, as we hope to capture insider trading surrounding market rumors and failed corporate events. Because insider trading is executed with the aim of being evasive and undetected, it is impossible to conclude with certainty. Nevertheless, using a hypothesized model based on how insiders and stock manipulators trade, we detect price patterns that are consistent with their objective to maximize profits and at the same time be evasive. * We are grateful to Donald Hanna, Naoyuki Yoshino, and Iikka Korhonen for their helpful comments.

No abstract