David Whittlesey

David Whittlesey


David focuses on complex commercial, business and intellectual property litigation. He has litigated numerous cases involving shareholder disputes, mergers and acquisitions, securities fraud claims, deceptive trade practices claims, patent infringement claims and trademark disputes.
In addition, he has significant experience with disputes relating to consumer products, license agreements, software, telecommunications, professional malpractice, trade secrets, real estate, insurance, banking, construction and oil and gas matters. He has represented clients in litigation and arbitration matters and in trial and appellate proceedings in several states and the District of Columbia. He also regularly counsels clients on compliance issues.


Representative matters


Lead counsel in numerous merger and acquisition disputes, representing both buyers and sellers in arbitrations and in litigation across several jurisdictions, including Delaware, Texas, New York, and California.

Represent certain defendants in consolidated securities litigation, regarding an alleged $1.8 billion “Ponzi scheme” purportedly orchestrated by GPB Capital Holdings, LLC and its owners.

Represented HPI Holdings, LLC in Delaware merger litigation brought by former stockholders of AdvantEdge Healthcare Holdings, Inc., who were seeking damages for alleged breach of an “earn-out” provision in the merger agreement. After full briefing and oral argument, obtained dismissal with prejudice of Plaintiffs’ “earn-out” claims on motion to dismiss.

Published Work

  • Shareholder Representative Servs. LLC v. HPI Holdings, LLC, No. 2022-0166-PAF, 2023 WL 3092895 (Del. Ch. Apr. 26, 2023)
  • In re Southland Royalty Co. LLC, 623 B.R. 64 (Bankr. D. Del. 2020)
  • Smith v. Premier Dermatology, No. 17 C 3712, 2019 WL 4261245 (N.D. Ill. Sept. 9, 2019)
  • Ontel Products Corp. v. YETI Coolers, LLC, 2017 WL 3033436 (D. N.J. 2017)

Speaking Engagements

  • Presenter, “Case in Point Webinar Series: Class Actions: Fundamentals & Trends” May 2017
  • Presenter, “Drafting Contracts and Related Legal Issues”, Belgian Economic Mission to the United States of America - Texas, December 2016
  • Presenter, “Trade Secret Claims Under the Texas Uniform Trade Secrets Act” September 2015
  • Presenter, “TexasBarCLE Essentials in Business Law Course” March 2015

Leadership Positions And Professional Affiliations

  • The General Counsel Forum, Board Member (2015-Current)
  • State Bar of Texas, Board Member, District 9 (2011-2014)
  • State Bar of Texas, Professionalism Committee (2015-2020)
  • Austin Bar Association, President (2010-2011); Secretary (2008-2009); Treasurer (2007-2008)


  • Profiled as a leading Commercial Litigation lawyer, The Best Lawyers in America®, 2013–2023
  • Ranked in Securities Shareholder Litigation (2015) and Securities Litigation – Defense (2016-2017), The US Legal 500
  • “Texas Super Lawyer”, Thomson Reuters, 2008–2020
  • “Texas Rising Star”, Thomson Reuters, 2005–2007



Texas, 1994


United States District Court for the Northern District of Texas, 1998

United States District Court for the Southern District of Texas, 1998

United States District Court for the Eastern District of Texas, 1998

United States District Court for the Western District of Texas, 1998

United States Court of Appeals for the Fifth Circuit, 1999

United States Supreme Court, 2012


B.B.A., University of Texas, Austin, 1991

J.D., The University of Houston Law Center, magna cum laude, 1994
– Houston Journal of International Law
– Order of the Coif 
– Order of the Barons

A&O Shearman was formed on May 1, 2024 by the combination of Shearman & Sterling LLP and Allen & Overy LLP and their respective affiliates (the legacy firms). Any matters referred to above may include matters undertaken by one or more of the legacy firms rather than A&O Shearman.