Mark H. Leeds is a Tax Transactions & Planning partner in Mayer Brown's New York office. His practice is focused on the tax consequences of a variety of capital markets, hedge fund, banking and insurance products and strategies, including over-the-counter derivative transactions, swaps, tax-exempt derivatives and strategies for efficient utilization of tax attributes—such as net operating losses. Mark regularly works on innovative insurance products and structures. Mark has extensive experience in working with businesses and individuals seeking to set up operations and relocating to Puerto Rico.

Mark advises on the tax aspects of capital markets, structured finance, derivatives, financial products and insurance transactions and has extensive experience working with both buyers and sellers to develop and structure complex derivatives, including litigation finance transactions. A significant portion of his work involves the taxation of financial products and trading strategies engaged in by banks and other financial market participants. He also advises on hedge fund and other investment vehicle formation matters. Mark does extensive work with digital assets, including cryptocurrencies, non-fungible tokens and blockchain transactions.

Mark is a former managing director and senior tax counselor with Deutsche Bank in New York. He also served as the general counsel of a credit derivative company and was a partner at Deloitte & Touche, where he led the capital markets tax practice.

Mark is a frequent writer and speaker on tax topics affecting capital markets and digital assets.


New York University School of Law, LLM in Taxation

Boston University School of Law, JD, magna cum laude

State University of New York at Binghamton, BA, cum laude


  • New York


  • Member, Committee of Banking Institutions on Taxation
  • Member, Institute of International Bankers
  • Member, New York State Bar Association, Tax Section
  • Member, American Bar Association
  • Member, The Tax Club
  • Member, International Swaps and Derivatives Association (ISDA)
  • Trustee, Best Buddies of New York