A.J. Monaco Partner

New York, New York




  • UCLA School of Law, Los Angeles, California J.D. - 2004
  • Dartmouth College B.A. - 1998

Bar Admissions

  • New York
  • New Jersey
  • California
  • U.S. District Court for the District of New Jersey
  • US. District Court Southern District of New York
  • U.S. District Court Eastern District of New York
  • U.S. Court of Appeals for the Second Circuit

Mr. Monaco is an experienced civil litigator who has represented clients in complex commercial matters for over twelve years. Since joining O’Brien LLP in October 2011, Mr. Monaco has represented cutting edge technology companies, e-commerce retailers, investment and commercial banks, private equity funds, hedge funds, and individuals in a wide array of commercial matters, including contractual disputes, defamation cases, and disputes involving fraud and breaches of fiduciary duty. He has seen numerous cases to a successful conclusion through trial or arbitration, and has experience mediating disputes as well. In addition to his litigation practice, Mr. Monaco is also a trusted advisor who counsels a diverse group of clients on a wide range of legal matters.

Prior to joining O’Brien LLP, Mr. Monaco worked at Sullivan & Cromwell, LLP, helping corporations and financial institutions respond to governmental investigations.

Notable Representations

  • Represented major international technology company accused of an array of business torts in State Court in New York, obtaining complete dismissal of all claims.
  • Represented influential e-commerce company in a contentious defamation dispute.
  • Represented hedge fund in a fee dispute with a former client, obtaining a successful arbitration award in the client’s favor.
  • Represented a private equity firm and its principal against a former executive employee who alleged breaches of contract and fiduciary duty in a dispute that spanned State and Federal Courts in three states. Successfully resolved the matter by obtaining a complete dismissal of all claims against the client.
  • Represented a managing member of a quantitative investment firm in an arbitration seeking to dissolve the partnership, resulting in the client retaining the exclusive rights to use the partnership’s intellectual property.
  • Successfully represented a multi-billion dollar hedge fund in an arbitration brought against a former employee for breach of a separation agreement.
  • Represented a hedge fund manager in a jury trial in Alabama, defending against breach of contract claims and pursuing claims of fraud and breach of fiduciary duty against a well-known public REIT. Obtained a verdict of $12.7 million, including punitive damages, and dismissal of all claims asserted against the client.

Published Works

Recent NY Appeals Court Rulings Clarify How Fund Managers May Pursue Former Employees for Breach of Fiduciary Duty and Improper Use of Performance Record,” The Hedge Fund Law Report, Vol. 9, No. 49 (December 15, 2016), by Sean R. O’Brien, A.J. Monaco and Michael Ahern.

“Defend Trade Secrets Act Provides Hedge Fund Managers With Protections for Proprietary Trading Technology and Other Trade Secrets,” The Hedge Fund Law Report, Vol. 9, No. 25 (June 23, 2016), by Sean R. O’Brien and A.J. Monaco.

How Can Hedge Fund Managers Protect Themselves Against Trade Secret Claims?,” The Hedge Fund Law Report, Vol. 7, No. 19 (May 16, 2014), by Sean R. O’Brien, Sara A Welch and A.J. Monaco.