This chapter addresses the demutualization process in a historical perspective and provides some explanations for its acceleration during the last two decades, as well as its slowdown after the 2008 financial crisis. It lists five clusters of reasons for demutualization: organizational isomorphism; cultural reasons; expropriation by managers; political preferences; and inefficiency or lack of growth perspectives. Connecting the cultural transformation that accompanied and supported privatization with the institutional isomorphism analysis, one could conclude that demutualization occurred where the new ideas of increased competition spread both quickly and deeply. During the seventies and the eighties, many of the cross-sectional studies of mutual and stock financial institutions pointed out the inefficiency of the mutual enterprises. The legal framework played a crucial role not only in allowing or interdicting demutualization, but also in creating an environment that makes demutualization appealing.