At the Q Group (the Institute for Quantitative Research in Finance) Spring Seminar, held 17–20 April 2016, Martin Leibowitz moderated a discussion of the important issues in finance by panelists Andrew W. Lo, Robert C. Merton, Stephen A. Ross, and Jeremy Siegel.  Editor’s note: We wish to thank the Q Group for allowing us to publish an edited version of this panel discussion, held 19 April 2016, and thus making the panelists’ comments available to a wide audience. Author Information Martin Leibowitz is a managing director at Morgan Stanley, New York City. Andrew W. Lo is the Charles E. and Susan T. Harris Professor of Finance at the MIT Sloan School of Management. Robert C. Merton is the School of Management Distinguished Professor of Finance at the MIT Sloan School of Management. Stephen A. Ross is the Franco Modigliani Professor of Financial Economics and a professor of finance at MIT and a managing member of Ross, Jeffrey, Antle, LLC. Jeremy Siegel is the Russell E. Palmer Professor of Finance at the Wharton School of the University of Pennsylvania.