In the previous decade and a half scores of microfinance institutions (MFIs) throughout the developing world have transformed into for-profit entities from non-profit origins or established themselves as brand new, specialized MFIs. While still few in number, shareholder-owned MFIs form an increasingly significant part of the financial landscape in developing countries and have joined banks and other traditional institutions as full-fledged members of the formal financial sector. Many of these institutions continue to experience rapid growth and must work constantly to increase their capital base. The ability of such MFIs to attract additional capital, above all from the private sector, will in large part determine the long-term success of their efforts.