An example of professor to billionaire, then back to professor.

David Elliot Shaw (born March 29, 1951) is a Jewish-American computer scientist and computational biochemist who founded D. E. Shaw & Co., a hedge fund company.

Shaw obtained his Ph.D. from Stanford University in 1980, then became a faculty member of the Department of Computer Science at Columbia University.  In 1988 he started his own hedge fund, "D. E. Shaw & Co.".  In 2007, Shaw was elected as a fellow of the American Academy of Arts and Sciences. In 2008, Forbes estimated his wealth to $2.5 billion.  In 2012, he was elected to the National Academy of Engineering.

Shaw is now Chief Scientist of D. E. Shaw Research, where he engages in hands-on research while leading an interdisciplinary research team in computational biochemistry. He is also a Senior Research Fellow at the Center for Computational Biology and Bioinformatics at Columbia University and an Adjunct Professor of Biomedical Informatics at Columbia's medical school.