David F. Swensen (born 1954) has been the Chief Investment Officer at Yale University since 1985. He is responsible for managing and investing the University's endowment assets and investment funds, which total $23.9 billion. Realizing an average annual return of 11.8 percent on his investments over the ten years to 2009, Swensen's consistent track record has attracted the notice of Wall Street portfolio managers. He is notable for inventing The Yale Model which is an application of modern portfolio theory. Swensen was listed third on aiCIO's 2012, a list of the 100 most influential institutional investors worldwide