Matthew M. Guiney
Partner, New York

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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 recovered over $7 billion for investors and $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, derivative law and employment law.

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


  • Lead counsel in numerous complex securities, 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 law breach of fiduciary duty claims. Successful litigation and negotiation of numerous multi-million dollar settlements, (for example, Brecher v. Citigroup, et al., 09-7359 (SHS) (S.D.N.Y.) ($8.5 million settlement); 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).
  • Argued and successfully achieved an injunction inIn 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 a pro bono program with the United States District Court for the Eastern District of New York. 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 honor of a former classmate.

Mr. Guiney also recently represented a client in the Eastern District of New York’s (Brooklyn) pro bono program where he helped the client achieve a unique settlement allowing the client to regain a disability pension.



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