Mr. Portnoy is a member of Davis Polk & Wardwell’s Litigation Department. He represents clients in a wide range of securities, commercial and antitrust matters in both federal and state courts and before various regulatory agencies. Mr. Portnoy has also represented clients in National Association of Securities Dealers, New York Stock Exchange and American Arbitration Association arbitrations.

Recently, Mr. Portnoy has represented investment banks and other financial institutions as well as industrial and manufacturing companies in class action litigations in federal district courts in New York, Massachusetts, New Jersey, Pennsylvania, Connecticut, Texas, California, Florida and the District of Columbia. He has also recently represented clients in state court matters in New York, Delaware, California and South Carolina and Securities and Exchange Commission enforcement matters, grand jury investigations, internal investigations and in connection with inquiries from various bank regulators, including the Federal Reserve Banks of New York, San Francisco and Chicago. Representative clients have included Credit Suisse First Boston, Morgan Stanley Comcast, F. Hoffman-La Roche, Deloitte & Touche, J.P. Morgan Chase, Bank of America, Alliance Capital and Sumitomo Mitsui.

Mr. Portnoy joined Davis Polk in 1989 and became partner in 1996.

He graduated from the University of Michigan, with highest honors, in 1985 and in 1988 received his J.D. from Harvard Law School. He clerked for the Honorable Ronald S.W. Lew of the U.S. District Court, Central District of California, from 1988 to 1989. He is admitted to the practice in New York and the District of Columbia and is admitted to the bars of the Federal District Courts for the Southern and Eastern Districts of New York, and the First, Second, Third, Fourth, Sixth and D.C. Circuit Courts of Appeals, and the U.S. Supreme Court.

Mr. Portnoy is a member of the New York State Bar Association Committee on Securities Litigation; the American Bar Association Committee on Class Actions & Derivative Suits; and the American Bar Association Committee on Pre-Trial Practice & Discovery.