This book analyses risk arbitrage in U.S. financial markets directed towards finance professionals and scholars.In particular, two research questions are pursued-(1) What are the effects of stock market, business conditions as well as the Merger and Acquisition Trend on risk arbitrage activities in the U.S (2) What is the current trend and effect of the U.S. financial regulatory mechanism on risk arbitrage? There has been a growing trend in US financial market regulatory mechanism to reduce systemic risk, eliminate legal uncertainty, control regulatory arbitrage and to have a closer look on derivatives trading which could be potentially used for fraud or manipulation. The current focus of the financial regulatory mechanism is to curb illegal trading in risk arbitrage activities through limits on trading volume and control of regulatory arbitrage opportunities which should continue into the future.