Stewart Mayhew

Vice President


  • Washington


Stewart Mayhew coheads Cornerstone Research’s corporate and government investigations practice. Dr. Mayhew is a financial economist with expertise in market regulation, government enforcement, and securities litigation. He specializes in securities trading, and works on matters related to option markets, market manipulation, insider trading, short selling, clearance and settlement, dark pools, and high-frequency trading. Dr. Mayhew is also an expert on the valuation of options and other derivative securities, and has extensive experience in securities class action litigation, including class certification, loss causation, and damages.

He has consulted for stock exchanges, broker dealers, investment banks, asset managers, hedge funds, and individuals involved in regulatory investigations and private litigation. Dr. Mayhew has also conducted studies connected to the rule making process as a contractor for the SEC and FINRA.

Prior to joining Cornerstone Research, Dr. Mayhew served as deputy chief economist of the U.S. Securities and Exchange Commission (SEC). His work at the SEC included regulatory matters related to stock, option, and bond markets; investment advisors; hedge funds; executive stock options; mutual fund distribution; proxy voting; exchange-traded funds; and structured products. In addition, Dr. Mayhew worked on numerous enforcement matters for the SEC.

Dr. Mayhew has held tenure-track faculty positions at Purdue University and the University of Georgia. He is a noted authority on option market structure and empirical option pricing, and has published articles in the Journal of Finance, the Review of Financial Studies, the Journal of Financial and Quantitative Analysis, and the Journal of Futures Markets.


In Re Allergan PLC Securities Litigation


City of Providence, Rhode Island, et al. v. BATS Global Markets Inc. et al.


Exchange-Traded Funds


Krukever et al. v. TD Ameritrade, Futures & Forex LLC


Facebook Inc. IPO Securities and Derivative Litigation

  • 2017 Corporate Governance Roundtable, Harvard Law School Program on Corporate Governance, 24 October 2017
  • “Responding to SEC/Regulatory Cross-Border and Domestic Inquiries,” Baker Botts, 21 January 2016