Microfinance has arguably been social innovation’s greatest success and biggest disappointment. It is the only social investment-driven initiative that has reached global scale (approximately 150 million clients worldwide) and created a complete ecosystem; and yet the impact on poverty has been far more muted than believed or hoped. Now the shine has come off the industry. Where does microfinance go from here? What are the most promising paths for innovation? What role do social investors have in improving client outcomes?