The banking and financial system of the WAEMU zone is the product of several eras that have marked its structure and activity. The system came into being following the installation of colonial banks, which were subsidiaries of Western banks and were rigorously managed. Over time, these banks underwent reforms that formed an integral part of the core liberalisation measures advocated by the community of donors and implemented under the aegis of the international financial institutions. With these reforms, the system was rebuilt and the profit rates posted by the main financial institutions in the franc zone are among the highest in the world. At the same time, the developed countries saw an acceleration of their financial markets, an unlimited quest for profit, a deregulation of the banking system followed by the appearance of new products, futures products, and excessive speculation. The bursting of the speculative bubble following mortgage lending led to a financial crisis knownas the sub-prime crisis, which spread and turned into an economic crisis.