Daniel W. Halston


Partner-in-Charge, Boston Office

Halston, Daniel W.

Daniel Halston focuses on securities litigation, general commercial litigation and administrative law disputes. He has represented numerous public and private high technology, life sciences, and financial services companies and their officers and directors in a wide range of complex litigation matters, including securities fraud class actions, derivative litigation, mergers and acquisitions disputes, false claims act actions, breach of fiduciary duty claims, investment advisor claims, closely-held corporation disputes, proxy contests, and a wide variety of public law matters. He also regularly represents clients in internal investigations and before the SEC, FINRA and state regulatory agencies. Mr. Halston serves as partner-in-charge of the Boston office.

Mr. Halston has represented numerous public and private companies and their officers and directors in complex securities, commercial, and corporate governance matters, including Airvana Corporation, BJ’s Wholesale Club, Inc., Berkshire Hills Bancorp, Inc., Biogen Idec, Eclipsys Corporation, Medtronic Inc., Separacor Inc., Sonus Networks, Inc., Staples, Inc. and State Street Corporation.

From 1991 to 1994, Mr. Halston served as an assistant attorney general in both the Administrative Law and Trial Divisions of the Government Bureau of the Massachusetts Attorney General's Office. He represented the Commonwealth before all courts of the Commonwealth in various disputes with regulated industries and professionals.

Recent Highlights

  • Obtained dismissal of merger-related claims against MKS Instruments, Inc. in Nevada State Court in 2017
  • Obtained dismissal of merger-related claims against Staples, Inc. based on exclusive forum by-law in Florida State Court in 2015
  • Obtained dismissal of derivative litigation against State Street Bank and Trust and its directors arising out of foreign exchange pricing allegations in District of Massachusetts in 2014
  • Obtained dismissal of merger-related claims against the directors of BJ's Wholesale Club, Inc. in Delaware Chancery Court in 2013
  • Successfully defended Berkshire Hills Bancorp, Inc. in Connecticut Trial Court in 2012 in a challenge to a merger, defeated an injunction after trial, and obtained dismissal of the case
  • Successfully defended Airvana Corporation in Delaware Chancery Court in 2010 in defeating expedited discovery sought against an acquisition, and obtaining a dismissal of the case
  • Represented Biogen Idec before the Massachusetts Supreme Judicial Court in 2009 in successful challenge to State Treasurer's enforcement of the abandoned property statute (Biogen IDEC MA, Inc. v. Treasurer, 454 Mass. 174 (2009))
  • Successfully defended a major pharmaceutical company in Massachusetts Superior Court in 2008 in defeating an injunction against a substantial merger transaction, and obtaining a dismissal of the case
  • Represented Sonus Networks, Inc. before the United States Court of Appeals for the First Circuit in 2007 and obtained dismissal of derivative litigation arising out of Company's Restatement (In re Sonus Networks, Inc. Shareholder Derivative Litigation, 499 F.3d 47 (1st Cir. 2007))
  • Represented a majority of the Board of Directors of the Massachusetts Turnpike Authority in corporate governance dispute with its now former Chairman in Massachusetts Supreme Judicial Court in 2006, and appointed as a Special Assistant Attorney General representing the Governor of Massachusetts in a successful effort to remove the Chairman from office
  • Obtained dismissal of securities fraud class action against Eclipsys Corp. in Southern District of Florida in 2004
  • Obtained dismissal of securities fraud class action against officers and directors of Triton Network Systems in Middle District of Florida in 2003
  • Successfully defended SinglePoint Financial Corp. against claim for advancement of attorneys' fees before Delaware Chancery Court and Delaware Supreme Court (Gentile v. SinglePoint Financial, Inc., 788 A.2d 111 (Del. 2001))
  • Represented many high technology, life sciences, and financial services companies in challenges to enjoin M&A transactions in Delaware Chancery Court and numerous state and federal courts
  • Represented several high technology clients in parallel securities fraud class actions, derivative litigation, FINRA and SEC enforcement proceedings, and internal investigations involving various conduct, including accounting fraud and stock-option backdating allegations

Publications & News


August 16, 2017

WilmerHale Lawyers Named Among the 2018 Best Lawyers in America®, Nine Recognized as Lawyers of the Year

Best Lawyers in America®—the oldest and most respected peer-review publication in the legal industry—recognizes 107 WilmerHale lawyers and names nine partners as Lawyers of the Year in its 24th edition.

June 13, 2017

One Year After Ambac: Sharing Information Among Deal Parties

In this Law360 article, Daniel Halston, Alexandra Boudreau and Jeffrey Schomig explain that the common interest doctrine remains a thorny issue one year after the major Ambac Assurance Corp. v. Countrywide Home Loans Inc. decision.

April 28, 2017

2017 M&A Report

Our 2017 M&A Report provides a detailed global M&A market review and outlook. Other highlights include takeover defenses for public companies; key lessons for buyers and sellers considering earnouts; recent developments in merger control regulation; common interest privilege protection among deal parties; special considerations in California M&A deals; acquisition financial statement requirements for IPO companies; a comparison of deal terms in public and private acquisitions; and key terms and issues in sales of VC-backed companies.

March 13, 2017

Death Knell to Merger Litigation for Massachusetts Corporations?

In IBEW Local No. 129 Benefit Fund v. Tucci, the Massachusetts Supreme Judicial Court (SJC) affirmed the dismissal of direct claims for breach of fiduciary duty by EMC shareholders challenging the merger of EMC and Dell, Inc. This WilmerHale Client Alert was republished in Bloomberg BNA's Mergers & Acquisitions Law Report.

August 15, 2016

WilmerHale Lawyers Named Among the 2017 Best Lawyers in America®, Six Recognized as Lawyers of the Year

Best Lawyers in America®—a respected peer-review publication in the legal industry—recognizes 101 WilmerHale lawyers and names six partners as Lawyers of the Year in its 23rd edition.

February 29, 2016

After In re Trulia: Increased Scrutiny for the Give and the Get in Disclosure Settlements

Early in the deal process, companies should seek advice on how best to reduce the risk of deal litigation and, if it arises, how best to navigate the realities of deal litigation during these changing times.

September 15, 2014

Delaware Court of Chancery Once Again Upholds Forum Selection Bylaw Requiring Intra-Corporate Litigation to Be Brought in a Forum Chosen by the Board of Directors

Once announced, merger and acquisition transactions typically result in the filing of numerous lawsuits in multiple jurisdictions. The Delaware Chancery Court has once again approved forum selection bylaw as a way to reduce the expense and distraction of multi-forum litigation.

June 25, 2014

US Supreme Court Decides Closely Watched Case on ERISA "Stock Drop" Class Actions

In Fifth Third Bancorp v. Dudenhoeffer, a decision written by Justice Breyer, the US Supreme Court unanimously held that plan fiduciaries are not entitled to any special “presumption of prudence” under the Employee Retirement Income Security Act of 1974 (ERISA) when they decide to buy or hold employer stock in an employee stock ownership plan (ESOP).

May 6, 2013

2013 M&A Report

Our 2013 M&A Report offers a detailed review of, and outlook for, the global M&A market. Other highlights include a discussion of the challenges and benefits of selling your company in a “dual-track” IPO, a comparison of public and private acquisitions, an analysis of issues and opportunities in California M&A deals, and a review of takeover defenses adopted by public companies. It also takes a look at the facts of life in M&A deal litigation, and survey key terms  in sales of VC-backed companies.

May 6, 2013

Deal Litigation: The Facts of Life

An article written by Daniel Halston, Nolan Mitchell and Andrew Dulberg.

Honors & Awards

  • Selected by his peers for inclusion in 2013-2018 editions of the Best Lawyers in America in the area of commercial litigation.
  • Named a "New England Super Lawyer" (formerly "Massachusetts Super Lawyer") in securities litigation in the 2004-2017 issues of Boston Magazine.
  • Recognized as a Massachusetts leader in general commercial litigation in the 2005-2012 editions of Chambers USA: America's Leading Lawyers for Business.
  • In 2012 survey by Best Lawyers, clients cite Mr. Halston as “an outstanding attorney who is well versed in handling and leading teams in complex investigation,” “trusted by his clients and adversaries alike,” and “much more than just litigation counsel. His experience, expertise and creativity allow him to serve as a trusted strategic advisor in arriving at a business resolution of disputes.”

Professional Activities

  • Director and Vice Chairman, Family Aid Boston
  • Member, Supreme Judicial Court Historical Society
  • Member, American Bar Association and Boston Bar Association
  • Former Lecturer, Boston University School of Law
  • Former Director, Massachusetts Appleseed Center for Law & Justice

Community Involvement

  • Town Meeting Member, Town of Belmont
  • Former Officer, Vassar Club of Boston


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JD, cum laude, Boston University School of Law, 1986, Executive Editor, Boston University Law Review

AB, with honors, Vassar College, 1982

Bar Admissions



US District Court for the District of Massachusetts, 1986 - 1987

Government Experience

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