Zachary J. Zweihorn
  1. Partner

Mr. Zweihorn is a partner in Davis Polk’s Financial Institutions Group and the trading and markets practice, practicing in the Washington DC office. His practice focuses on the regulation of broker-dealers and other securities market participants and intermediaries, including advising on SEC, FINRA and securities exchange rules relating to the conduct of business, financial responsibility, margin, market structure and related compliance obligations. He also advises clients on regulatory matters in connection with mergers and acquisitions, capital markets and finance transactions involving broker-dealers and securities exchanges, including obtaining regulatory approvals where necessary. His clients include major international banks, broker-dealers, securities exchanges, digital asset and blockchain businesses, and other financial institutions. He also helps clients to advocate in connection with regulatory and legislative proposals and has assisted clients in drafting proposed language for legislation, including aspects of three bills that have become law.

Work Highlights

Regulatory Advice

  • Assisting a major electronic market maker to conduct a comprehensive review of its compliance and surveillance practices and best execution analysis framework
  • Advising Long-Term Stock Exchange on its application for registration with the SEC as a national securities exchange and strategic arrangement with IEX
  • Advising a broker-dealer operating an alternative trading system on regulatory considerations in connection with a novel product and service offering
  • Advising various cryptocurrency market participants on securities law compliance considerations
  • Assisting major investment management firm to obtain FINRA approval for a new broker-dealer subsidiary
  • Advising numerous non-U.S. financial firms regarding their U.S. activities, including compliance with Rule 15a-6

Transactional Advice

  • Charles Schwab Corporation on its $1.8 billion acquisition of assets of USAA’s Investment Management Company, including brokerage and managed portfolio accounts
  • Charles Schwab Corporation on its $26 billion all-stock acquisition of TD Ameritrade Holding Corporation
  • Morgan Stanley on its $13 billion acquisition of E*TRADE Financial Corporation
  • SS&C Technologies in connection with its acquisition of DST Systems, the owner of the ALPS fund distribution broker-dealers
  • Lightyear Capital in connection with its acquisition of Wealth Enhancement Group, a retail wealth management advisory and brokerage firm, and sale of Clarion Partners, a real estate investment firm and affiliated broker-dealer
  • Bats Global Markets in connection with its acquisition of Direct Edge, its initial public offering, and its sale to CBOE Holdings
  • Crestview Partners in connection with its equity investment in Arxis Capital Group, an electronic trading firm that specialized in the automated market making of global securities, and its acquisition of Victory Capital, an investment firm and broker-dealer
  • Underwriters in connection with the SEC-registered initial public and subsequent follow on offerings of common stock of Virtu Financial, Inc., a technology-enabled market maker and liquidity provider to the global financial markets
  • J.P. Morgan in connection with National Bank of Canada’s $150 million issuance of a one-year floating-rate Yankee certificate of deposit and parallel simulation of the issuance using J.P. Morgan’s blockchain technology
  • Ad hoc group of pre-petition secured second-lien term lenders in connection with the chapter 11 bankruptcy cases and related financing transactions involving Aretec Group, Inc. and Cetera Financial Holdings, Inc., the parent company of the Cetera Financial Group network of retail broker-dealer firms


  • Chambers USA – Financial Services Regulation: Broker Dealer (Compliance), Nationwide, Up and Coming
  • "Zachary Zweihorn impresses clients with his knowledge of securities law, broker-dealer regulation and SEC and FINRA rules. One client says: 'Zach is one of the most knowledgeable young attorneys in this area, having dealt with a myriad of complex regulatory issues.'" – Chambers USA editorial

Of Note

  • Co-Author, “What is a Broker-Dealer?,” Practicing Law Institute, Broker-Dealer Regulation (Second Edition)
  • Thought Leader on Financial Regulation, Davis Polk FinReg Blog, read Mr. Zweihorn's posts
  • Frequent speaker on developing areas of securities regulation

Professional History

  • Partner, 2020-present
  • Counsel, 2015-2020
  • Associate, 2007-2015
  • Washington DC office, 2010-present
  • New York office, 2007-2010

Bar Admissions

  • District of Columbia
  • State of New York


  • B.A., CUNY Queens College, 2004
    • Phi Beta Kappa
    • summa cum laude
  • J.D., Cornell Law School, 2007
    • Order of the Coif
    • magna cum laude
    • Editor, Cornell Law Review