In addition to managing his family office, Grand Teton Holdings, Inc. since 2013, Mark is Founding Principal at AQR Arbitrage since 2001, and is Adjunct Professor of Finance at The University of Chicago since 2017.Prior to co-founding AQR Arbitrage in 2001, Mark was a finance professor at the University of Chicago and at Harvard University where he authored numerous research papers about mergers & acquisitions, arbitrage strategies, and numerous other economic and financial topics. During Mark's tenure in academia at Chicago and Harvard, he won four paper-of-the-year awards and five teaching awards. To this day, Mark continues to be actively involved in writing academic research papers. A long-time board member at TD Ameritrade, Mark was the only director to have served on the TD Ameritrade board from its IPO until its ultimate sale to Charles Schwab in late 2020. Mark served on numerous committees during his tenure as a board member at TD Ameritrade: Audit, HR & Compensation, M&A (Chair), Outside Independent Directors, Risk (Chair), Special (Chair), and Strategic Development.In other board experience, Mark served on the board of CNH Finance, a specialty-finance firm during its entire history (2014-2022) until it was acquired by eCapital Corporation, Gainskeeper, Inc. (2000-2002) until acquired by Wolters Kluwer, Frontier Airlines Unsecured Creditors Committee (2008-2009), NASD Economic Advisory Board (1996-1998), NASDAQ Quality of Markets Committee (2003-2005), and Alternative Investment Forum (2010-current). In February 2007, Mark served as an emissary of the U.S. State Department to discuss M&A with policymakers, business leaders, academics, and reporters in Japan. After obtaining a M.A. in Economics and Ph.D. in Applied Economics at Clemson University, Mark began his career in the Office of the Chief Economist at the U.S. Securities & Exchange Commission where he worked during 1987-1990. At the SEC, Mark authored several research papers, worked on merger regulations, and led the development of applying financial economics to assist the SEC's enforcement actions in insider trading cases. According to The Wall Street Journal editorial board, Mark's research at the SEC was "not only excellent, but also pertinent economic history."