Margaret Isa Butler has nearly 20 years of experience, primarily focused on mergers and acquisitions, joint ventures and alternative investments.

She regularly represents private equity fund managers, institutional investors, independent sponsors and family offices across the investment strategy spectrum. Margaret has experience handling multimillion-dollar deals, as well as those ranging into the billions of dollars, and her experience also extends to private placements, real estate development projects and limited partner investments, debt and equity co-investments and direct investments. She has also advised clients on conflicts and other governance issues for funds, corporations and other entities. Further, her substantial deal advisory and implementation experience allows her to execute sophisticated private equity and hedge fund transactions, design custom structures for investments, and engage in all aspects of mergers and acquisitions, including public company takeover defense and shareholder activism.

Margaret’s extensive experience is rooted in her background as an investment banker for a multinational financial services company, as well as in her education, having earned an M.B.A., which enables her to take a multifaceted approach to each transaction.


Prior to joining Armstrong Teasdale, Margaret was in private practice at another New York area law firm.

Before that, she worked for an international law firm where she oversaw mergers and acquisitions of publicly traded companies, engaged in buy-side and sell-side representation in private transactions, provided advice with respect to activist hedge fund investment techniques and related securities law issues, and represented pension plans on fund investments. Further, before entering private practice, Margaret spent several years as an investment banker for a multinational financial services company.


  • Harvard College  (B.A., cum laude, 1996)
    • Social Studies
  • Columbia Business School  (M.B.A., 2002)
    • Beta Gamma Sigma (Honor Society, Inducted Member)
  • Columbia Law School  (J.D., 2002)
    • Columbia Law Review (Editor)
    • James Kent Scholar (Top Academic Award)


  • New York
  • New Jersey

Professional Activities

  • cmorq, Organized Blockchain Data (General Counsel)
  • New York City Bar Association, M&A Committee  (2009-2012; 2018-present)
  • War Chest Women Podcast (Founder)

Charitable and Civic Involvement

  • The Ellsworth Institute (Founder and CEO)
  • Brash NYC (Co-Founder)
  • Columbia Business School, Hispanic Business Alumni Club (Co-President, 2019-present)
  • Columbia Business School, Alumni Club of South Florida (Board Member)
  • Columbia Business School, Private Equity Program (Advisory Board, 2012-2016)
  • Columbia Business School, Entrepreneurship Class (Guest Instructor, 2014-present)
  • New Vic Council at the New Victory Theater (Committee Member)
  • Lehman Center for the Performing Arts (Board of Directors)
  • Harvard Club of New York Mergers and Acquisitions Group (Leader)
  • The Foundation for Gender Equality (Board Member, 2017)


  • Chambers USA Award for Excellence, Real Estate (2017) (methodology)
  • New York Metro Super Lawyers®, Rising Star (2014) (methodology)
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  • The M&A Advisor, "40 Under 40" (2013)
  • Euromoney Legal Media Group’s Americas Women in Business Law Awards, “Corporate Rising Star" Shortlist (2013)
  • Team member for one of "America’s Best Corporate Law Firms," Corporate Board Member magazine and FTI Consulting Inc., 13th Annual Legal Industry Study (2013)


  • Spanish
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