David Swensen, Yale's Chief Investment Officer and manager of the University's endowment, discusses the tactics and tools that Yale and other endowments use to create long-term, positive investment returns. He emphasizes the importance of asset allocation and diversification and the limited effects of market timing and security selection. Also, the extraordinary returns of hedge funds, one of the more recent phenomena of portfolio management, should be looked at closely, with an eye for survivorship and back-fill biases.