/ / Matthew M. Guiney

Matthew M. Guiney is a partner at Wolf Haldenstein and practices in complex class actions representing public and labor pension funds, labor health and welfare benefit funds, and private institutional investors who suffered losses due to corporate fraud. He is a member of the Firm’s litigation team that has recovered more than $7 billion for investors and more than $300 million for workers. Mr. Guiney is also a member of the Firm’s Investor Protection, Consumer Protection and Labor and Business Practice litigation groups with an emphasis on securities law, consumer protection law and employment law.

Mr. Guiney has appeared at the United States Supreme Court (spring 2018), has argued at federal and state appellate courts (as recently as May 2018) and argued at trial courts at the federal and state level across the country.

Mr. Guiney joined the firm as an associate in 2004 and became partner in 2012.


  • Appeared at the United States Supreme Court on behalf of the plaintiffs/respondents in China Agritech v. Resh, No. 17-432 (S. Ct.) (opinion pending).  Served as counsel of record and briefed opposition to petition for writ of certiorari.
  • Argued and achieved reversal of motion to dismiss in a published opinion in the United States Court of Appeals for the Ninth Circuit in Resh v. China Agritech, No. 15-5543, 2017 U.S. App. LEXIS 9029 (9th Cir. May 24, 2017).
  • Lead counsel in numerous complex securities, consumer, employment and derivative litigations in both federal and state courts concerning the Securities Act of 1933, the Exchange Act of 1934, the Employee Retirement Income Security Act of 1974, the Fair Labor Standards Act of 1938, and numerous state consumer protection laws. Successful litigation and negotiation of numerous multi-million dollar settlements, serving as lead or co-lead counsel (for example, Brecher v. Citigroup, et al., 09-7359 (SHS) (S.D.N.Y.) ($8.5 million settlement after successful motion to dismiss briefing); Mallozzi v. Industrial Enterprises of America, Inc., et al., No. 07-10321 (GBD) (S.D.N.Y.) ($3.8 million settlement); In re Luxottica Group S.p.A. Securities Litigation, No. 01-3285 (JBW) (E.D.N.Y.) ($18.25 million settlement); In re IsoRay, Inc. Securities Litig., No. 15-5046 (LRS) (E.D. Wa.) ($3.575 million settlement after successful motion to dismiss briefing); Kachun Wong v. Baker Tilly Hong Kong, Ltd., Case No. 14-cv-9959-CBM (C.D. Cal.) ($925,000 auditor settlement after successful motion to dismiss briefing).
  • Argued and successfully achieved an injunction in In re Integrated Silicon Solution, Inc. Stockholder Litig., 1-15-CV-278812 (Sup. Ct. Santa Clara, CA 2015) (injunction requiring corrective disclosures concerning “don’t-ask-don’t-waive” standstill agreements and certain financial advisor conflicts of interests, and contributing to the integrity of a post-agreement bidding contest that led to an increase in consideration from $19.25 to $23 per share, a increase of almost 25%).
  • Litigating several matters in federal appellate courts in both the United States Second and Ninth Circuit Courts of Appeals.


Mr. Guiney participates in the Eastern District of New York’s (Brooklyn) pro bono program where he recently helped a client achieve a unique settlement allowing the client to regain a disability pension.   Mr. Guiney also helps to organize an annual charity golf outing that raises scholarship funding for diverse students to receive a private school education at his alma mater high school in New York City in honor of a former classmate.



Bar Admittance