Joy O. Siu

Joy Siu is an associate in the Antitrust and Competition Practice Group in the firm’s San Francisco office.

Areas of Practice

Joy’s practice focuses on litigating antitrust and competition cases arising under the Sherman and Clayton Acts, as well as state antitrust, consumer protection, and unfair competition statutes in multidistrict litigation, class actions, and private civil suits. Joy also has substantial experience representing companies before the government during merger review and in investigations by federal agencies and state attorneys general into alleged violations of antitrust and consumer protection laws, including the Sherman Act, Robinson-Patman Act, Section 5 of the FTC Act, and product mislabeling and deceptive advertising claims. She represents clients across a broad array of industries, including food and beverage, healthcare, cement, construction, consumer electronics and retail, artificial intelligence, digital advertising, and automotive software and finance.

Joy is an active alumna of UC College of the Law, San Francisco (formerly UC Hastings), where she has served on the Board of Governors since 2016 as the Co-Chair of the Employment and Employer Relations Committee and former Co-Chair of the Student Liaison Committee. She has also taught Legal Research and Writing at the school and currently serves as a mentor to students in the Women’s Law Society and Honors Society.

Honors

"Ones to Watch," Best Lawyers, 2024-2025

Northern California Rising Star, Super Lawyers, 2019-2025

Recommended Lawyer: Antitrust - Civil Litigation/Class Actions: Defense, Legal 500, 2023

Articles

Antitrust Law Blog

• "Cement and Concrete Admixture Price Fixing Conspiracy Allegations Not Strong Enough to Survive Motion to Dismiss," July 9, 2025

• "Campaign Promises to Address Rising Prices at the Grocery Store Signal Stronger Price Gouging Investigations, Enforcement Actions, and Prohibitions to Come," November 1, 2024

• "Final Word on Final Rule? Texas District Court Eviscerates FTC’s Non-Compete Ban," August 21, 2024

• "FTC Votes to Ban Noncompete Agreements," April 24, 2024

• "The FTC Hosts Workshop on Private Equity in Health Care," March 6, 2024

• "AI Under the Antitrust Microscope: Competition Enforcers Focusing on Generative AI from All Angles," August 9, 2023

• "A Big Deal: FTC and DOJ Issue Long-Awaited New Draft Merger Guidelines," July 20, 2023

• "DOJ Loses Third Consecutive Antitrust Labor Trial," March 24, 2023

• "Maybe the FTC Can’t Take That to the Bank: The Supreme Court’s Decision in Liu v. SEC and Its Implications for the FTC’s Ability to Seek Equitable Monetary Relief," July 13, 2020

Class Action Defense Strategy Blog

• "Ninth Circuit Slams the Brakes on Nationwide Class Action Settlement; Choice of Law and Reliance Are Bumps in the Road," February 1, 2018 
• "Dancing On Their Own: The California Supreme Court’s Decision in McGill v. Citibank, N.A. that Class Action Waivers Do Not Apply to Claims for Public Injunctive Relief under California’s Consumer Protection Laws,"  April 7, 2017

Construction Law Blog Posts

• "It’s All a Matter of [Statutory] Construction: Supreme Court Narrowly Interprets the Good Faith Dispute Exception to Prompt Payment Requirements in United Riggers & Erectors, Inc. v. Coast Iron & Steel Co." May 16, 2018 
• "'Good Faith' May Not Be Good Enough: California Supreme Court to Decide When General Contractors Can Withhold Retention," March 7, 2018 
• "Picerne Construction Corp. v. Castellino Villas (Feb. 18, 2016, C071197)," January 23, 2017

Media Mentions

Events

Digital Media