Robert Greffenius’s practice consists of representing individuals and entities in a broad range of governmental and internal investigations, including matters involving the Securities and Exchange Commission (SEC), the Department of Justice (DOJ), the Federal Reserve Board, state attorneys general, securities self-regulatory organizations and foreign regulatory agencies. His representations have included responding to multi-faceted and multi-jurisdictional regulatory investigations, special litigation committee inquiries, alleged accounting irregularities and alleged insider trading. He also advises broker-dealer clients on regulatory compliance issues such as best execution and Regulation NMS.

Prior to joining the firm, Mr. Greffenius was an associate at a prominent law firm in Washington DC, where his practice focused on securities investigations conducted by the SEC and DOJ. During his time there, he co-authored an article analyzing insider trading matters involving misappropriation of information by family and friends. He also participated in a fellowship program at The Constitution Project, where he helped research and draft a report on data privacy and government data mining.

Mr. Greffenius also served as a voluntary law clerk to the Hon. Reggie B. Walton of the US District Court for the District of Columbia.


  • Recognized as a "Rising Star" for securities litigation in the 2022, 2021 and 2020 editions of Washington DC Super Lawyers

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  • Education

    • JD, American University, Washington College of Law, 2009

      magna cum laude Order of the Coif, Senior Articles and Critical Essays Editor, American University International Law Review, Legal Writing and Rhetoric Dean’s Fellow
    • Washington University in St. Louis, 2004

      Dean’s Scholarship
  • Admissions

    • District of Columbia

    • New York



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