T he focus on risk arbitrage in the finance literature has increased in recent years. The major issues have been the profitability of the risk arbitrage strategy, the relationship between the success of takeovers and the positions held by arbitrageurs, the supply of arbitrage capital and the overall role of arbitrageurs in the takeover process. To examine these issues or draw conclusions effectively, researchers need to understand the behavior of risk arbitrageurs.This article seeks to provide specific information about the role and behavior of risk arbitrageurs. This information can be used to examine the validity of some assumptions in the current literature and aid researchers in making valid assumptions in their future research.Until recently, very little has been known about the role of arbitrageurs and the inner workings of the risk arbitrage decision process. Therefore researchers have made various assumptions related to the role and behavior of risk arbitrageurs. For example, Mitchell and Pulvino [2001] made various assumptions about position limits and restrictions on the capital of arbitrageurs. In addition, the lack of knowledge of the behavior of risk arbitrageurs has given rise to various debates in the literature. For example, several researchers (e.g., Cornelli and Li [2002]) have hypothesized that sizable positions held by arbitrageurs contribute to the positive abnormal returns of the takeover. On the other hand, Larcker and Lys [1987] hypothesize that arbitrageurs earn abnormal returns by being better informed than the market about the probability of each deal's success. The results presented in this article will provide researchers with information on the activity of risk arbitrageurs in the marketplace. These results should help clarify a number of matters relevant to the topic.This article explores two related issues. First, the authors obtain private information on arbitrageur holdings in two takeover transactions from recent years. Most prior research has approximated the holdings of arbitrageurs by examining filings at the Securities and Exchange Commission (SEC). The authors obtain this data from a leading proxy solicitation firm. Second, in order to gain a better understanding of the process of arbitrage and the behavior of risk arbitrageurs, the authors report the results of a survey of a significant group of active arbitrageurs. The survey results provide insights on the risk arbitrageur activities during the merger/acquisition process.The article makes four contributions. First, the results provide the evidence about how quickly arbitrageurs become involved in the trading in securities involved in takeovers. Previous published research has made assumptions as to the speed of involvement of the risk arbitrage community.Second, the authors explore in the survey how arbitrageurs structure their portfolios and how they control risk within these portfolios.