Professionals

Susannah Torpey

Partner

Co-Chair, Technology Antitrust Group

Admitted to practice only in New York

Overview
Experience
Credentials
Insights & News

Co-Chair of Winston’s Technology Antitrust Group, Susannah is a Litigation Partner with more than twenty years of experience representing Fortune 500 companies in multimillion and billion dollar antitrust class actions, high-tech competitor litigations, international investigations, and counseling partnerships. She has been repeatedly recognized as a Client Choice Award Winner, “SuperLawyer,” “Top Woman Attorney,” and as a “Star” in Antitrust and Litigation for obtaining critical wins for her clients, whether at trial on behalf of plaintiffs or by winning complete dismissals on behalf of defendants. She has also been recognized as one of the “Top Women Leaders in Law,” “Top 50 Women Leaders in Technology,” as a “Global Elite Thought Leader,” and as a “high-tech expert.” Susannah has further been recognized for her “ability to add real value to clients’ business above and beyond the other players in the market” based on clients’ praise for her “subject matter expertise;” “exceptional knowledge and capability to handle complex antitrust matters;” “deep understanding of the operative case law” and ability to apply “this knowledge deftly to the important economic and market issues that underlie these cases;” as well as her “ability to quickly understand the nuances of [her clients’] business.” Susannah has also been commended as “an expert in her field [who] knows how to target her advice to achieve business results;” “an incredibly effective advocate” who is highly regarded for “handling complex oral arguments;” as a “very trusted and valued advisor;” and as “an excellent outside counsel advisor and a very experienced antitrust litigator.”

Susannah litigates cutting-edge issues at the evolving intersection of antitrust, IP, and technology. Susannah has more than twenty years of experience representing leading companies and competitors in the preparation, trial, and appeal of complex antitrust cases. She regularly represents plaintiffs, as well as defendants, and has represented clients in both civil and criminal matters, including in international criminal antitrust investigations.

Susannah regularly represents major U.S. and multinational corporations in high-profile, multidistrict, and class action litigation and government investigations involving a wide array of federal and state antitrust issues, including monopolization, monopoly leveraging, price fixing, wage fixing, no-poach agreements, group boycotts, exclusive dealing, tying, price discrimination, unfair competition, anticompetitive product redesign, interoperability degradation, and mixed issues of antitrust and intellectual property law relating to Fair, Reasonable, and Non-Discriminatory (FRAND) obligations, standard-setting, patent licensing, patent misuse, and fraud on the PTO. Susannah also routinely counsels international and U.S. businesses regarding the minimization of antitrust risk, pricing strategies, antitrust compliance, and business issues relating to the use of tech and IP, many of which are key to a company’s global strategy.

Susannah has represented and counseled clients in a variety of industries and in connection with a wide array of technologies, including: wireless connectivity (2G-5G); semiconductors, numerous computer and memory products; artificial intelligence; apps; IoT; ecommerce and data platforms; adtech; open source software, VoIP; fintech; electronic trading; blockchain; crypto; DAOs; patent aggregation and licensing; pharmaceutical; medical devices; biotech; chemical processing; crude oil; steel products and fabrication; food products and distribution; publishing; professional sports; international trade; consulting; and financial services industries.

During law school, Susannah served as a judicial intern to the Honorable Delissa A. Ridgway of the U.S. Court of International Trade. She also served as a legal intern in the Criminal Division of the DOJ.

Key Matters

Antitrust, Class Action, and MDL

Represents a Fortune 50 technology company in a high-profile antitrust litigation relating to artificial intelligence
Represents a Fortune 500 company in a high-profile, multidistrict antitrust lawsuit against Keurig alleging monopolization, conspiracy, group boycott, tying, exclusive dealing, unfair competition, anticompetitive product redesign, patent misuse, and sham litigation claims. Our clients’ litigation was followed by more than 30 class actions, In re Keurig Green Mountain Single-Serve Coffee Antitrust Litigation and has garnered attention from top media outlets including CNN, USA Today, The Guardian, Law360, and multiple industry publications
Represents pharmaceutical companies in an antitrust litigation alleging monopolization, conspiracy, unfair competition, and false advertising claims
Served as lead antitrust counsel and successfully argued and obtained complete dismissal of claims alleging data monopoly and related conspiracy and unfair competition claims
Served as lead counsel for a Fortune 500 defendant multinational financial services company and obtained complete dismissal and affirmance on appeal of monopolization, conspiracy, tortious interference, RICO, and breach of contract claims relating to purported conspiracy to breach contractual obligations not to challenge patent in inter partes review
Served as lead antitrust counsel for a public marketing company and successfully obtained dismissal of antitrust claims alleging fraud on the PTO and monopolization
Served as lead antitrust counsel for a Fortune 500 multinational financial services company and obtained complete dismissal of monopolization, exclusive dealing, price fixing, and tying claims relating to misappropriation of proprietary code and intellectual property purported to cover fintech banking apps
Successfully obtained and defended on appeal a complete dismissal of a high-profile antitrust litigation nominated for GCR Litigation of the Year and "Litigator of the Week" recognition on behalf of a wireless connectivity patent portfolio company of claims alleging monopolization, conspiracy, group boycott, unfair competition, and breach of contract claims relating to purported FRAND obligations and joint licensing conduct
Successfully obtained a complete dismissal for a Fortune 500 global investment bank in a multi-billion dollar MDL antitrust class action involving U.S. Treasuries and derivatives markets, In re Treasury Securities Auction Antitrust Litigation
Successfully obtained a favorable settlement for plaintiff multinational technology company in a high-profile monopolization, conspiracy, unfair competition, and patent misuse litigation, which garnered attention from news outlets such as Reuters News, Law360, Channel Partners News, Telecompaper, Optical Networks Daily, and Fin Examiner
Successfully obtained dismissal on behalf of Panasonic Corporation and Panasonic Corporation of North America of a major putative class action alleging a price-fixing conspiracy and unfair competition claims in connection with an SD Card standard-setting organization and joint venture, obtaining disqualification of the initial lead opposing counsel and firm
Successfully obtained dismissal on behalf of Panasonic Corporation in an antitrust litigation alleging conspiracy and monopolization claims in connection with an SD Card standard-setting organization
Served as lead antitrust counsel in case resulting in favorable settlement for client pursuing monopolization and sham litigation claims based on anticompetitive assertions of intellectual property relating to chemical processing of crude oil
Represented Panasonic Corporation and Panasonic Corporation of North America in the multidistrict, putative class action, optical disk drive products antitrust litigation. Successfully defeated class certification with a decision highlighted by the Daily Journal as one of the Top 20 Defense Verdicts of 2014, In re Optical Disk Drive Antitrust Litigation
Represented Plaintiff Feesers, Inc. through the course of its litigation, including a successful appeal before the Third Circuit Court of Appeals, and at trial, which was also successful, in its action against a leading food service management company and a food supplier concerning allegations of Robinson-Patman Act violations
Represented a Fortune 500 steel company plaintiff in an antitrust litigation concerning monopolization, conspiracy, exclusive dealing, unfair competition, patent misuse, and sham patent litigation resulting in successful elimination of challenged exclusive dealing agreement
Successfully persuaded plaintiff to drop claims asserted against a patent assertion entity in antitrust litigation concerning alleged FRAND obligations and a purported conspiracy to split patent royalties
Represented a Fortune 500 global investment bank in a multi-billion dollar MDL antitrust class action involving credit derivatives markets, In re Credit Default Swaps Antitrust Litigation
Represented a Fortune 500 steel producer in an antitrust litigation concerning alleged conspiracy, price discrimination, and trade secret misappropriation
Represented seven of the world’s top poker players in a conspiracy and group boycott antitrust lawsuit filed against the World Poker Tour

Antitrust and FCPA Government Investigations

Represented multinational corporation before FTC relating to competitor acquisition
Represented multinational corporations in international criminal antitrust investigations of global cartels requiring the coordination of responses to government agencies spanning various jurisdictions across Asia, Europe, and the United States
Represented Fortune 500 multinational corporation in major investigation assessing potential no poach and wage-fixing agreements for compliance with antitrust laws
Represented multinational corporations spanning Asia, Europe (including Russia and the Commonwealth of Independent States), the Middle East, and the United States in parallel FCPA investigations by the DOJ and SEC
Manages large-scale internal investigations to evaluate compliance with antitrust laws and to assess whether companies should apply for leniency with the DOJ

Antitrust Counseling

Counsels companies in connection with new tech design to minimize antitrust risk relating to new products
Counsels international and U.S. corporations regarding antitrust risks associated with information exchanges, most-favored-nation clauses, hiring and recruitment practices, licensing practices, assertions of IP, unilateral “Colgate” policies, pricing structures, price discrimination, resale price maintenance, minimum advertised pricing (or MAP) programs, algorithmic pricing, bidding, territorial restrictions, and other vertical resale restrictions in connection with both internet and brick-and-mortar distribution systems
Served as general antitrust counsel to an internet marketing, ecommerce, and data analytics joint venture platform throughout the formation, tech design and development, and successful sale of the start-up to a third party
Counsels joint ventures and affiliated companies in connection with minimization of competitively sensitive information exchanges, firewalls, potential spillover conduct, and no poach issues
Counsels international corporations regarding Sherman Act and Robinson-Patman Act jurisdiction over foreign activities and the Foreign Trade Antitrust Improvements Act

Antitrust Compliance, Internal Investigations, Audits, and Training

Represented a joint venture before DOJ and state Attorneys General to investigate and certify antitrust compliance with consent decree
Conducted nationwide internal investigation to ensure antitrust compliance and mitigate risk of potential criminal liability for Fortune 500 company
Designs and institutes antitrust compliance programs
Provides antitrust training to corporate employees

U.S. Supreme Court and Other Complex Litigation

Represented Medimmune, Inc., in several suits relating to monoclonal antibody technology. One of these cases led to the U.S. Supreme Court’s landmark decision in Medimmune v. Genentech, 127 S. Ct. 764 (2007), which expanded the right of patent licensees to challenge the validity of licensed patents.
Served as amicus counsel on behalf of the Texas Association Against Sexual Assault in the matter of Hegar v. Texas Entertainment Association, Inc., before the U.S. Supreme Court.
Served as amicus counsel on behalf of Professor J. Shugerman in the matter of Lacaze v. State of Louisiana regarding an individual’s due process right to an impartial judiciary before the U.S. Supreme Court.
Served as amicus counsel for Educational Fund to Stop Gun Violence in the matter of McDonald v. City of Chicago before the U.S. Supreme Court.
Represented the Executive Committee of the Coalition for Fair Lumber Imports in a constitutional challenge in the U.S. Court of Appeals for the D.C. Circuit to the dispute resolution procedures of NAFTA.
Successfully obtained summary judgment on behalf of a financial lending client for the dismissal of breach of fiduciary duty claims.

Recent Experience

Secured High-Profile Fifth Circuit Dismissal for Avanci of Closely Watched Technology-Antitrust Case

In 2025, Susannah was named as one of the top “500 Leading Global Antitrust & Competition Lawyers” by 2025 Lawdragon and was selected as the sole Lexology Client Choice Award winner for Competition/Antitrust from New York and as a “Global Elite Thought Leader.” Susannah was honored in 2024 and 2025 as one of the “Top Women Leaders in Law” and in 2024 as one of only two Lexology Client Choice Award recipients in the Competition/Antitrust category in the United States and the exclusive winner in the Competition USA New York category. Lexology’s Client Choice Award recognizes “partners around the world that stand apart for the excellent client care they provide and the quality of their service” based on their “ability to add real value to clients’ business above and beyond the other players in the market.” She was also recognized by Benchmark Litigation US as a “Litigation Star” (2019–2025) and as a “National Practice Area Star” in Antitrust (2024–2025). Susannah was further named as one of the “Top 50 Women Leaders in Technology” in both 2022 and 2023 in Women We Admire and listed as a “Key Lawyer” in The Legal 500 U.S. 2021–2023 for Antitrust Civil Litigation/Class Actions: Defense. She has been regularly selected since 2018 to the New York Super Lawyers list and the Rising Stars list before then. She is also consistently recognized in the list of “Top Women Attorneys in the New York Metro Area” published by New York Times Magazine. In 2022, Susannah was on the team honored with “Litigator of the Week” recognition for their important Fifth Circuit antitrust win, which was also nominated for GCR’s 2022 “Litigation of the Year” award. In 2020, Susannah was part of the group awarded “Law Firm of the Year” for its Antitrust/Competition practice by U.S. News & World Report – Best Law Firms and “Antitrust Firm of the Year” by Benchmark Litigation US. In 2019, Susannah was part of the group recognized as a Tier 1 National “Best Law Firm” by U.S. News – Best Lawyers. In 2018, Susannah was part of the group named as “Antitrust Firm of the Year” by Benchmark Litigation US as well as “Trial Group of the Year” by Law360. In 2016, she was awarded “Best Business General Antitrust Article” for her article entitled, “Human Resources: The Next Antitrust Frontier” from the 2016 Antitrust Writing Awards. In 2015, she was part of the group recognized as the “Cartel Defense Group of the Year.” In 2014, the denial of class certification she worked on was recognized as one of the “Top Defense Verdicts” of the year. Susannah has also been honored by being selected as a Fellow of the American Bar Foundation in recognition as a “lawyer whose career has demonstrated outstanding dedication to the highest principles of the legal profession and to the welfare of society.”

Capabilities

Antitrust/Competition

Technology Antitrust

Commercial Litigation & Disputes

Government Investigations, Enforcement & Compliance

Class Actions & Group Litigation

Litigation/Trials

Intellectual Property

Compliance Programs

Trade Secrets, Non Competes & Restrictive Covenants

Patent Litigation

Technology, Media & Telecommunications

Cryptocurrencies, Digital Assets & Blockchain Technology

Financial Services

Media & Entertainment

Medical Devices

Sports

Professional Services

Food & Beverage

Artificial Intelligence (AI)