Professor Geanakoplos is a Founding Partner and Vice Chairman, overseeing Research and Development. During the first decade of Ellington, he created the theoretical framework, still currently in use, for Ellington’s proprietary agent-based prepayment models, and led the development of computer systems for evaluating and hedging the firm’s agency mortgage portfolio.
From 1992 until joining Ellington in 1995, Professor Geanakoplos was a Managing Director of Kidder Peabody, where he was head of the Fixed Income Research Department. In that capacity, he led the design of the firm’s proprietary MBS analytical systems.
Geanakoplos became a full Professor at Yale University in 1986, at the age of 30, and is currently the James Tobin Professor of Economics. He is best known for his work on what he called the Leverage Cycle, which emphasizes changes in lending standards (especially margins) in driving economic cycles. From 1996-2005 he was Director of the Cowles Foundation for Research in Economics, and from 1991 until today he has been Chair of Hellenic Studies. In 2019-20 he was Chair of the Yale Faculty of Arts and Sciences Senate. He was elected a fellow of the Econometric Society in 1990 and of the American Academy of Arts and Sciences in 1999. He was awarded the Samuelson Prize in 1999, and was awarded the first Bodossaki Prize in economics in 1995. In 1990 and again in 2000, he directed the economics program at the Santa Fe Institute, where he remains an external professor. In 1970 he won the United States Junior (under 20) Open Chess Championship.
Professor Geanakoplos graduated summa cum laude, Phi Beta Kappa with a Bachelor of Arts in Mathematics from Yale University and received a Master of Arts in Mathematics and a Doctor of Philosophy in Economics from Harvard University, under the supervision of Ken Arrow.