Risk Arbitrage is one of the most innovative areas of quantitative asset management. Its best quality is getting back low volatility yields poorly correlated to benchmark. This book pursues few goals. Firstly, Risk Arbitrage is placed into a theoretical framework using the Statistical Arbitrage(SA) Theory. Secondly, the most common SA strategies are shown starting from Pairs Trading (with Stochastic Approach and Cointegration Approach). The next step counts on breaking down High Frequency strategies which represent one of the most popular set of techniques in highly volatile markets. Finally, the review of SA strategies is extended to modules exploiting inefficiencies related to behavioral phenomena. The last section looks for answering the question how investors can apply SA to 130/30 products.