Alison Plessman

Alison L.



  • Columbia Law School (J.D., 2003)
  • University of Minnesota (B.A., 1999, Political Science) summa cum laude
  • California
  • New York
“This securities litigator wins big, particularly when her clients are the biggest on earth.”
—“Lawyers on the Fast Track,” The Recorder
“She’s highly regarded as a real up-and-comer.”

Alison L. Plessman consistently delivers successful outcomes for high-profile clients faced with complex, challenging business, regulatory, and criminal matters. She represents both plaintiffs and defendants in high-stakes commercial litigation matters in several areas, including securities, health care and insurance fraud, trade secrets misappropriation, RICO violations, accounting irregularities and market manipulation, professional negligence, and breaches of contract and fiduciary duties. She also has successfully defended companies, boards of directors, and individuals facing regulatory investigations and criminal enforcement actions, securing many pre- and post-indictment dismissals.

In 2015, 2017, and 2018, Ms. Plessman was selected by the Daily Journal as one of the Top 100 Women Lawyers in California. In 2013, Ms. Plessman was selected by The Recorder as one of only 50 “California Lawyers on the Fast Track.”

Ms. Plessman began her legal career as a litigation associate at Wachtell, Lipton, Rosen & Katz in New York City before joining Irell & Manella, where she was elected partner.

During law school, Ms. Plessman was named a Harlan Fiske Stone Scholar and won the Frederick H. Weisberg Award in Constitutional Law. As an undergraduate, she was a member of Phi Beta Kappa and Phi Kappa Phi.


Represented Broadcom in a copyright and breach of contract dispute against Walmart leading to an expedient and favorable resolution.

Representing Southern California Edison and Edison International in litigation arising out of the 2017 Thomas Fire and 2018 Montecito mudslides.

Representing senior executive of Plantronics, Inc. in a trade secrets dispute against Cisco currently pending in the Northern District of California.

Represented InterDent, Inc. in breach of contract dispute with Levine Leichtman Capital Partners, II, L.P. leading to a full dismissal of the case following a successful summary judgment motion.

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Represented a Hong Kong investment company in multiparty RICO and breach of contract action alleging violations of U.S. export control laws leading to a successful motion to compel arbitration between third parties and stay of the litigation with respect to the client.

Represented Western Digital and its SanDisk subsidiaries in their widely publicized dispute with Toshiba over anti-transfer provisions in joint venture agreements governing the manufacture and development of NAND flash memory. The dispute encompasses multiple ICC arbitrations and litigation in the California trial and appellate courts, where SanDisk secured injunctive relief in aid of the arbitrations.

Defended a leading global professional services company against an $830 million actuarial malpractice lawsuit brought by the city of Houston in connection with the city’s $6.2 billion pension crisis and obtained a favorable settlement.

Served as trial counsel for T-Mobile in a successful trade secrets lawsuit against the Chinese smartphone maker Huawei Technologies alleging the manufacturer stole T-Mobile’s smartphone testing robot.

Obtained $20 million for Pacific Life against Bank of New York Mellon at the summary judgment stage in a breach of contract and breach of fiduciary duty matter in investment mismanagement litigation, later obtaining an additional $30 million for Pacific Life in a settlement on the eve of trial.

Obtained a settlement for only attorneys’ fees, after filing a motion for summary judgment, in a professional liability matter against a security assessment firm facing alleged damages of over $150 million.

Represented Universal Music Group in a nine-figure negligence and breach of contract lawsuit concerning media assets that were destroyed in a fire at NBC Universal’s studio lot. Reached a favorable settlement shortly before the start of trial and after successfully adding a punitive damages claim.

Successfully defended an investment bank professional in a U.S. Treasuries probe conducted by the SEC and the Commodities Future Trading Commission, resulting in no charges or fines.

Successfully defended a senior executive at a global investment firm in a multiyear investigation being conducted by the SEC, resulting in no charges or fines.

Defended a senior executive at an international gaming company in whistleblower suit investigated by the SEC, resulting in no charges or fines.

Represented Glaukos against a claim of inequitable conduct in a complex patent matter in Delaware federal court. The case was settled three days before trial on favorable terms for our client.

Won a dismissal of a criminal mortgage fraud indictment after evidentiary hearings for prosecutorial misconduct. (See “Judge Dismisses Case Against Oil Heir Hill, Finds Dallas DA in Contempt,” The Dallas Morning News).

Served on the winning trial team in the $2.2 billion insurance dispute between Silverstein Properties and several insurance companies concerning the collapse of the World Trade Center in the aftermath of the September 11 attacks.

Successfully defended Kenneth Langone’s Invemed Associates in a disciplinary proceeding before the National Association of Securities Dealers (NASD, now FINRA) that resulted in what The New York Times called a “withering” and “high-profile defeat” for the regulators.

Represented the New York Stock Exchange (NYSE) in litigation with dissident seatholders following the announcement of the NYSE’s historic merger with Archipelago. During the preliminary injunction hearing, the parties reached a settlement that allowed the vote on the merger to proceed as scheduled.


  • Top Women Attorneys, Los Angeles Business Journal
  • “Top 100 Women Lawyers” in California, Daily Journal (2015, 2017, 2018, 2019)
  • Named to the Southern California Super Lawyers list (2016-2019)
  • Named to the Super Lawyers Rising Stars list (2013-2014)
  • 50 “California Lawyers on the Fast Track,” The Recorder (2013)


Board Member, Western Center on Law & Poverty

Member, Women’s White Collar Defense Association


“Electronic Discovery and the Proposed Amendments to the Federal Rules of Civil Procedure,” Securities Litigation Reporter
“Lessons from Moussaoui: The Ethics of Witness Prep,” New York Law Journal