The banking failures occurred during the current financial crisis have soon thrown financial creeds into chaos. In fact, in August 2007 many of the literature assumptions crashed down together with the stock indexes. The regulatory system of Basel II and the aggressive attitudes of financial investors toward a massive use of securitisation deals soon went on trial, referred to as as some of the triggering causes involved in the crime scene, represented by the breakout of a financial boom at the global level. Do they represent the only causes underlying such a shame in the financial landscape? This book attempts to investigate on the motives of such a disaster affecting the financial world as a whole. How can an efficient and profitable bank be such instable to fail? What are the triggering drivers and dynamics behind this? In other words, which is the real inner relationship between stability and efficiency in the banking system? This book analyzes whether they are synonymous or not and at which extent.