Shaun J. Mathew, P.C.

Partner Shareholder Activism & Hostile Takeover Defense

New York +1 212 909 3035

Shaun J. Mathew, P.C.

Overview

Shaun is a visionary. He sees the whole picture and is able to provide clients with all the possible solutions to a situation while clearly articulating the pros and cons of each solution. - Chambers USA, Takeover Defense, 2021–2026

Shaun is a corporate partner and the leader of the Firm’s Shareholder Activism & Hostile Takeover Defense practice, which was recognized by its peers as the #1 activism defense law firm practice in 13D Monitor’s 2025 qualitative league tables. Shaun is recognized as one of the 500 leading lawyers in America across all practice areas by Lawdragon (the only activism lawyer on the list), and as among the top lawyers for activism and takeover defense by Chambers USA (Band 1) and The Legal 500 US (Leading Lawyer).

Shaun is a frequent speaker on shareholder activism and corporate governance. He has appeared on Bloomberg TV and has guest lectured at Harvard Law and Michigan Law School, among others. His articles have been featured in Harvard Law School Forum on Corporate Governance, and he has been quoted in leading publications including The Wall Street Journal, The Financial Times, The New York Times, The Deal and Law360.

In his practice, Shaun counsels public companies and their boards in defending live proxy fights, negotiating truces with activist hedge funds, responding to short attacks, defending M&A deals against activist opposition, as well as guiding companies through complex corporate governance and other crisis matters.

His experience includes defending public companies and private equity sponsors in several of the most high profile challenges to M&A transactions, and he has defended clients against campaigns mounted by a number of activist investors including Elliott Management, Starboard Value, Politan Capital Management, Carl Icahn and JANA Partners.

Select Experience Highlights

  • Southwest Airlines in resolving Elliott Management’s threatened special meeting proxy contest seeking to replace its CEO and a majority of the board
  • Wyndham Hotels in its successful defense against Choice Hotels $8 billion hostile takeover bid and full slate proxy fight
  • Huntsman Corporation in its successful defense of a proxy contest by Starboard Value
  • Bristol-Myers Squibb in its successful defense of its $90 billion acquisition of Celgene against opposition by Starboard and Wellington
  • AIM ImmunoTech in its successful defense of two proxy contests (including the first attempted proxy contest under the SEC’s universal proxy rules)
  • Vincent McMahon (controlling stockholder of WWE), on actions in support of a plan for WWE to undertake a review of strategic alternatives, including the election of Mr. McMahon and two others to the WWE board, and in the subsequent $21+ billion merger of WWE and UFC
  • Victoria’s Secret & Co. in its successful defense of a “vote no” proxy fight launched by BBRC International
  • KKR in its strategic partnership agreement with Henry Schein, including its strategic investment and agreements regarding the composition of the board and collaboration on range of value creation initiatives

Shareholder Activism Defense

  • Six Flags Entertainment Corporation in connection with its agreements with H Partners regarding the composition of the Six Flags board, shareholder activism by Land and Buildings, its CEO transition and its $8 billion merger of equals with Cedar Fair
  • Acadia Healthcare in response to activism by Engine Capital and Khrom Capital
  • Sabre in its strategic governance agreement with Constellation Software
  • Constellation Brands in connection with its cooperation and information sharing agreements with Elliott Management
  • Lee Enterprises in its successful defense of a hostile takeover bid and attempted proxy contest by Alden Global Capital
  • Wynn Resorts in its response to the “withhold-the-vote” campaign by Elaine Wynn and its agreement with Elaine Wynn regarding the composition of the Wynn Resorts board of directors
  • Azenta in its cooperation agreement with Politan Capital Management
  • Clear Channel Outdoor in its cooperation agreement with Legion Partners
  • HanesBrands in connection with its cooperation agreement with Barington
  • Heron Therapeutics in connection with a cooperation agreement with Rubric Capital and Velan Capital
  • Sylvamo in connection with its cooperation agreement with Atlas Holdings
  • Anywhere Real Estate in connection with its cooperation agreement with TPG Angelo Gordon
  • Mueller Water Products in connection with its cooperation agreement with Ancora Holdings
  • Travelport Worldwide Limited in response to shareholder activism by Elliott Management and in its $4.4 billion sale to Siris Capital and Elliott
  • KVH Industries, Inc. in its successful defense against a proxy contest led by VIEX Capital
  • Taubman Centers in connection with shareholder activism by Land and Buildings
  • Del Frisco’s Restaurant Group, Inc. in its agreement with Engaged Capital regarding the composition of the board
  • Avantor in response to activism by Engine Capital
  • Avis Budget Group in its defense against multiple proxy contests by SRS Investment Management and an agreement with SRS regarding the composition of the Avis Budget Group board of directors
  • Vitamin Shoppe in its defense against a full slate proxy contest by Vintage Capital, its agreements with Vintage Capital and Shah Capital regarding the composition of the Vitamin Shoppe board of directors, and its acquisition by Liberty Tax
  • Daseke in connection with its cooperation agreements with Don Daseke and Lyons Capital regarding the composition of the Daseke board
  • CBL in its agreement with Exeter Capital regarding the composition of the CBL board of directors
  • KVH Industries, Inc. in connection with its cooperation agreement with Vintage Capital Management, LLC regarding the composition of the KVH Industries board
  • Tenneco Inc. in connection with its cooperation agreement with Protean Services LLC and Daniel A. Ninivaggi regarding the composition of the Tenneco board
  • Lee Enterprises in response to the “withhold-the-vote” campaign by Cannell Capital
  • Laredo Petroleum in connection with shareholder activism by SailingStone Capital Partners
  • Xerox in its agreement with Carl Icahn and Darwin Deason regarding the composition of the Xerox board of directors

Defense of Activist Challenges to M&A Transactions

  • Thoma Bravo in its successful defense of its acquisition of Dayforce against opposition by T. Rowe Price
  • Vista Equity Partners in its successful defense of its acquisition of Model N against opposition by ClearBridge Investments
  • ONEOK in its successful defense of its acquisition of Magellan Midstream Partners against opposition from Energy Income Partners
  • Thoma Bravo in its successful defense of its acquisition of Magnet Forensics against opposition by Nellore Capital Management
  • Vista Equity Partners in its successful defense of its acquisition of Avalara against a proxy contest by Altair US, LLC
  • Starwood Capital Group in its successful defense of its $6 billion joint acquisition, together with Blackstone Real Estate Partners, of Extended Stay America Inc. against a proxy contest by Tarsadia Capital
  • Vista Equity Partners in its successful defense of its acquisition of Pluralsight against a proxy contest by Eminence Capital
  • Thoma Bravo in its successful defense of its acquisition of Instructure against opposition by Praesidium and Rivulet Capital
  • Callon Petroleum Company in its successful defense of its $3.2 billion acquisition of Carrizo Oil & Gas against opposition by Paulson & Co. Inc.
  • Steiner Leisure (an L Catterton portfolio company) in its successful defense of its PIPE investment in OneSpaWorld against opposition by Deep Field Asset Management
  • Vista Equity Partners in its successful defense of its acquisition of Mindbody against opposition by Luxor Capital
  • Rowan Companies plc in its successful defense of its $12 billion merger with Ensco against opposition by Canyon Capital
  • WellCare Health Plans in its successful defense of its $17.3 billion acquisition by Centene Corporation against opposition by Third Point, Sachem Head and Corvex

Wachtell Lipton Rosen & Katz

Vinson & Elkins LLP

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Thought Leadership

Seminars

“Which governance pressure is defining 2026?” Outstanding Directors Exchange, Financial Times (June 2026)

2026 Activism Summit, Kirkland & Ellis in partnership with Gordon Haskett (May 2026)

“Activism in 2026: Emerging Trends,” Bloomberg Activism Forum 2025 (December 2025)

“Shareholder Activism Case Study: Starboard’s Proxy Fight Against Huntsman Corp.,” Guest Lecture, Harvard Law School (November 2025)

“Shareholder Activism Case Study: Starboard’s Proxy Fight Against Huntsman Corp.,” Guest Lecture, Michigan Law School (November 2025)

“Shareholder Engagement: State of Play,” Society for Corporate Governance (September 2025)

“Annual Corporate Law Symposium: Developments in Texas and Delaware,” The Journal of Corporation Law (September 2025)

“Shareholder Activism and Shareholder Engagement,” Stanford Directors’ College (June 2025)

“Activist campaigns and board readiness - Defending against the next campaign,” Outstanding Directors Exchange, Financial Times (June 2025)

2025 Activism Summit, Kirkland & Ellis in partnership with Gordon Haskett (May 2025)

“Advanced Notice Bylaws,” Institute for Corporate Governance & Finance Spring Roundtable, NYU School of Law (May 2025)

“Shareholder Activism and M&A Landscape,” Acquisitions of Public Companies Subcommittee Meeting, American Bar Association, Business Law Section, New Orleans Conference (April 2025)

“Shareholder Activism Takeover Defense & Related Delaware Litigation,” Guest Lecture, Professor Vikramaditya Khanna, University of Michigan Law School (April 2025)

“Shareholder Activism Takeover Defense & Related Delaware Litigation,” Guest Lecture, Professor Roberto Tallarita, Harvard Law School (April 2025)

“Activism and Hostile M&A: What to Expect in 2025,” Kirkland & Ellis Webinar (November 2024)

“Shareholder Activism Litigation,” Guest Lecture, M&A Litigation (Prof. Jesse Fried), Harvard Law School (November 2024)

“Activism Preparedness: A Tabletop Exercise,” Ray Garrett Jr. Corporate & Securities Law Institute (September 2024)

“Crisis Anticipation and Management,” Stanford Directors’ College (June 2024)

“Corporate Governance in Detail: What is the Board Agenda for 2024?” Outstanding Directors Exchange, Financial Times (June 2024)

“Case Law Matters: Delaware’s Recent Stockholder Activism Jurisprudence,” American Bar Association, Business Law Section, Orlando Conference (April 2024)

“Disruption within the Boardroom: Shareholder Activism and Beyond,” Ascend Pinnacle Board Leadership Summit (March 2024)

“Emerging Issues in M&A, Shareholder, Activism and Crisis Situations,” Mori Hamada & Matsumoto Japan Webinar (March 2024)

“Shareholder Activism and the Evolving Social & Political Crisis Landscape: What Directors Need to Know,” Ascend Pinnacle, Dallas (January 2024)

“Barbarians at the (Universal Proxy) Gate: Shareholder Activism & How Companies Can Prepare,” National Asian Pacific American Bar Association (November 2023) 

“Universal Proxy: Fallout and Future,” Council of Institutional Investors Webinar (July 2023) 

“The New Shareholder Activism Vulnerability Landscape: Universal Proxy and The Market Downturn. What You Need to Know and How to Prepare for the Upcoming Proxy Season,” Kirkland & Ellis Webinar (October 2022)

“Voting in Corporate Elections,” Guest Lecture, Corporate Lawyer (Prof. Vikramaditya Khanna), University of Michigan Law School (February 2022) 

“Activism & ESG Developments: Lessons from the Exxon / Engine No. 1 Proxy Context and the 2021 Proxy Season,” Texas General Counsel Forum (July 2021)  

“Shareholder Activism and Corporate Control Contests in Practice,” Guest Lecture, Corporate Lawyer (Prof. Vikramaditya Khanna), University of Michigan Law School (April 2020)

“Disclosure in Public M&A,” Guest Lecture, Mergers and Acquisitions (Chief Justice Strine), Harvard Law School (November 2019)

Publications

“Activism, Hostile M&A and Other Corporate Crisis: Preparing For a Raid In Times of Turbulence,” Corporate Disputes (September 2025)

“Bridge Over Troubled Waters: Five Ways Public Companies Can Prepare for Shareholder Activism in Times of Turbulence,” Kirkland Governance Update, Harvard Law School Forum on Corporate Governance, Wolters Kluwer’s Insights (April 2025, June 2025)

“Shareholder Activism: Lessons from the First Season of Universal Proxy,” Kirkland M&A Update (June 26, 2023)

“Crisis Preparedness in the Rapidly Evolving Vulnerability Landscape,” Kirkland Governance Update (June 8, 2023)

“Lessons from Huntsman’s Proxy Fight Victory Over Starboard,” Harvard Law School Forum on Corporate Governance (May 1, 2022) 

“SEC Proposes New Cybersecurity Disclosure Regime for Public Companies,” Kirkland M&A Update (March 14, 2022)

“On the Record(holder) — With Universal Proxy on Horizon, Delaware Confirms Importance of Up-to-Date and Unambiguous Advance Notice Bylaws,” Harvard Law School Forum on Corporate Governance (March 13, 2022)

“Crossing the Board-er Line: Issues to Cor When an Executive is Invited to Join an Outside Public Company Board,” Kirkland M&A Update (November 16, 2021)

“r/BlackRockAnnualLetter: Climate Change and ESG in the Age of Reddit,” Harvard Law School Forum on Corporate Governance (February 16, 2021)

“REIT Activism Trends to Expect in the Wake of COVID-19,” Law360 (October 2, 2020)

“Poison Pills — A Measured Prescription,” Kirkland M&A Update (March 24, 2020)

"#MeToo Compliance — Two Years In, “Wait-and-See” Is No Longer An Option," Kirkland Governance Update (October 3, 2019)

"New SEC Policy for No-Action Requests to Exclude Rule 14a-8 Shareholder Proposals for 2019–2020 Proxy Season," Kirkland Governance Update (September 9, 2019)

“Purpose, Culture and Long-Term Value — Not Just a Headline,” Harvard Law School Forum on Corporate Governance (February 26, 2019)

“Surviving Activist Shareholders, Passive Index Funds and Corporate Crises,” Corporate Board Member (September 10, 2018)

“Shareholder Activism: Evolving Tactics,” Harvard Law School Forum on Corporate Governance (August 23, 2018)

“Advance Notice Bylaw Deadlines: A Warning Shot,” Harvard Law School Forum on Corporate Governance (May 26, 2018)

“Advance Notice Bylaws – Advantage Confirmed,” Kirkland M&A Update (April 16, 2018)

“Takeaways from BlackRock’s 2018 CEO Letter,” Law360 (January 26, 2018) 

Recognition

Band 1, Chambers USA, Corporate/M&A: Takeover Defense - New York, 2026

“Leading Lawyer,” The Legal 500 United States, Shareholder Activism: Advice to Boards, 2019–2026

Recognized by Lawdragon as one of the 500 Leading Lawyers in America, 2024–2026

Recognized by Lawdragon as one of the 500 Global Leaders in Crisis Management, 2025–2026

Memberships & Affiliations

Journal of Corporation Law (Editorial Board)

Harvard Association of Law and Business (Co-Chair, Alumni Advisory Board)

NYU Lawyer Alumni Mentoring Program (Advisory Board)

Ashoka Foundation (Ashoka Support Network)

Credentials

Admissions & Qualifications

  • New York
  • Texas

Education

  • Harvard Law SchoolJ.D.cum laude

    Founder, Harvard Association of Law & Business

  • New York UniversityB.A., Economics & Politicssumma cum laude
  • London School of Economics and Political ScienceGeneral Course

Press Mentions & Media Appearances

Interviewed, “Activist Investors Changing Their Approach: Mathew,” Bloomberg Deals (April 8, 2026)

Interviewed, “New SEC 13G/13D Guidance Impacting Shareholder Engagement & What Directors Need to Know,” Stanford Rock Center for Corporate Governance (April 2025)

Interviewed, “Shareholder Activism Muted Despite SEC Rule,” Bloomberg TV (June 28, 2023) 

Quoted, “How a SEC rule change has opened more doors for activists,” The Financial Times (June 24, 2023)

Quoted, “Corporate America is bracing for a rise in activist investing. Meet the 13 lawyers on speed-dial when companies and investors fight for boardroom control,” Insider (November 23, 2022)

Quoted, “Companies Brace for Onslaught of New Activists After Change in Proxy-Voting Rules,” The Wall Street Journal (November 20, 2022) 

Quoted, “The Universal Proxy Rule is Not Universally Loved,” The New York Times DealBook (November 19, 2021)

Quoted, “Nasdaq Diversity Rule To Bring Change, Or Shame, To Cos.,” Law360 (August 13, 2021)

Quoted, “Activist Defense Law Firm of the Year,” The Deal (September 2020)

Quoted, “The Activist Insight 2019 Adviser Awards,” Activist Insight Monthly (December 2019)

Quoted, “Another Summer of Discontent,” The Deal's Dealmaker Quarterly (September 26, 2019)

Quoted, “M&A, Active Managers Among Catalysts for H1 Insurgencies,” The Deal (August 30, 2019)

Quoted, “Activist Investors Gain Clout as Stocks Tumble,” The Wall Street Journal (December 26, 2018)