Noted by Chambers USA as “an established figure for both his commercial and securities litigation practices,” Marc J. Sonnenfeld defends class actions asserting violations of the federal securities laws, derivative cases, claims arising from mergers and acquisitions, and appraisal actions, as well as regulatory and enforcement proceedings. Marc has argued numerous successful motions to dismiss, including recent victories in the Sixth, Seventh, and Ninth Circuits, and been recognized for his extensive trial experience.
Marc leads the defense of putative securities class actions and derivative cases around the United States having won motions to dismiss (many of which he argued) in 13 cases since 2009. At the federal and state level, he has successfully defeated challenges to merger transactions collectively valued in excess of $10 billion. He advises boards and has been counsel to board committees.
Among his appellate victories are an issue of first impression under the federal securities laws addressed by the Ninth Circuit, Retail Wholesale & Department Store Union Local 338 Retirement Fund v. Hewlett-Packard Co. (9th Cir. 2017), and two seminal cases deciding corporate governance issues under Pennsylvania law, Cuker v. Mikalauskas (1997) (amicus curiae), and LeMenestrel v. Warden (2008) (appellee).
A fellow of the International Academy of Trial Lawyers and American College of Trial Lawyers, Marc’s trial and appellate experience includes cases involving shareholder issues, such as appraisal trials and a challenge to the sale of a business, as well as cases with commercial claims. One of Marc’s trials was featured in a trial practice book, Trying Cases to Win: Anatomy of a Trial by Herbert J. Stern and Stephen A. Saltzburg.
Marc was selected as an Acritas Star Lawyer as a result of an 18-month long survey of nearly 4,000 general counsel and other senior leaders at legal departments around the world. Marc was chosen as a 2013 “Client Service All-Star” by BTI Consulting Group, and as one of five attorneys named “Securities MVP” by Law360 in 2012. Marc has been named one of Philadelphia’s top business litigators in The Best Lawyers in America since 1997, being selected as a “Securities Lawyer of the Year” in 2013. He has been included by Philadelphia Magazine as one of the 100 “Pennsylvania Super Lawyers” and was named “The Securities King of Pennsylvania” by Super Lawyers Magazine (2016) in a cover story profile.
Marc is active in bar activities and was awarded the 2010 Wells Fargo Fidelity Award from the Philadelphia Bar Association for his work developing and maintaining the Commerce Court Program in the Philadelphia Court of Common Pleas. He has served as chair of the Philadelphia Bar’s board of governors and co-chair of its Business Court Task Force.
After graduation from law school, Marc served as a law clerk to Judge Joseph S. Lord III, then Chief Judge of the US District Court for the Eastern District of Pennsylvania.
In Retail Wholesale & Department Store Union Local 338 Retirement Fund v. Hewlett-Packard Co. (9th Cir. 2017), which Marc argued, the Ninth Circuit affirmed the district court’s dismissal of securities fraud claims based on the company’s ethics code and statements relating to it, ruling that there had been no affirmative misrepresentation because the statements were not objectively verifiable, that any alleged misrepresentation was not material and that there was no duty to disclose any supposedly omitted facts “[b]ecause the affirmative statements did not create the impression of full compliance.” News coverage of this opinion is linked to this bio.
In Doshi and City of Livonia Emps. Ret. Sys. v. General Cable Corp. (6th Cir. 2016), which Marc argued, the Sixth Circuit Court of Appeals affirmed the district court’s dismissal of a putative class action alleging violations of the federal securities laws based on two restatements, finding that plaintiff had not adequately pled scienter.
In Plumbers and Pipefitters Local Union 719 Pension Fund v. Zimmer Holdings, Inc. (7th Cir. 2012), which Marc argued, the Seventh Circuit Court of Appeals affirmed the district court’s dismissal of a putative class action case alleging violations of the federal securities laws based on a purported product flaw and FDA Form 483 observations.
In LeMenstrel v. Warden (Pa. Super. 2008), which Marc argued, the Pennsylvania Superior Court affirmed the dismissal of derivative claims after an evidentiary hearing tried by Marc in an opinion defining the proper scope for attorney lawyer involvement in an investigation by a special litigation committee and adopting the definition of “disinterested” and “independent” under Pennsylvania law.
In Verition Partners Master Fund Ltd. and Verition Multi-Strategy Master Fund Ltd. v. Aruba Networks, Inc., (Del Ch. 2018), the Delaware Chancery Court ruled in favor of Aruba Networks, Inc. in an appraisal case, following a 2016 trial and post-trial briefing, including a motion for reargument. This victory was widely report in Law360, the Financial Times, and The Deal. Coverage of the case is linked to this bio.
Recent Denial of Injuction
In Ehrlich v. Arconic Inc. (C.C.P. Phila. Cty. 2017), Marc served as co-counsel and in five days filed a motion to reconsider an order granting sweeping expedited discovery (which was granted), an opposition to an emergency motion for preliminary injunction and preliminary objections to the complaint. After a hearing on the emergency preliminary injunction motion, the court denied the request to issue a preliminary injunction that challenged the board’s actions during a proxy fight. The court found that plaintiff failed to prove either irreparable harm or that greater injury would result from refusing the injunction than granting it. The preliminary objections are pending. At the hearing, Marc argued Pennsylvania law issues relating to standing under the Pennsylvania and Corporations Law and venue.
Motions To Dismiss Granted By Trial Courts And Not Appealed
Plumley v. Sempra Energy (S.D. Cal. 2017), the district court dismissed putative class action claims alleging violations of the federal securities laws arising from the natural gas leak at the Alison Canyon natural gas facility. The court examined both pre-leak and post-leak statements and found that plaintiff failed to plead facts showing that the challenged statements were false or that defendants acted with scienter. The court allowed plaintiff 21 days in which to file an amended complaint addressing the deficiencies that it identified.
In Hussey v. Ruckus Wireless, Inc. (N.D. Cal. 2017), the district court granted with prejudice a motion to dismiss Section 14 claims finding that plaintiff had abandoned its Section 14(d)(7) claims and failed to state a Section 14(e) claim because scienter is required and was not pled, nor was falsity adequately pled. Media coverage of this decision is linked to this bio.
In Cockle v. Coustas (Marshall Islands 2013), which Marc argued the High Court of the Republic of the Marshall Islands granted the motion to dismiss the derivative suit based on claims relating to payment of management fees and terms of a private financing.
In Scheiner v. Midas, Inc. et al (N.D. IL. 2013), the district court granted the motion to, dismiss a Section 14 action, challenging the Form 14d-9 for the acquisition of Midas by TBC.
In Zucker v. Andreessen (Del. Ch. 2012), which Marc argued, the Delaware Court of Chancery granted the motion to dismiss derivative claims, based on the severance package awarded to the company’s former CEO.
In Saginaw Police & Fire Pension Fund v. Hewlett-Packard Company (N.D. Cal. 2012), the district court granted the motion to dismiss derivative claims based on the board’s alleged failure to prevent FCA and FCPA violations. Plaintiff appealed to the Ninth Circuit but dismissed its appeal days before oral argument was scheduled.
In Gammel v. Hewlett-Packard Company (C.D. Cal. 2012), which Marc argued, the district court granted the motion to dismiss a putative securities fraud class action based on the company’s announcement that it was discontinuing development of an operating system and associated products. In 2013, the district court granted in part the motion to dismiss a further amended complaint, cutting the putative class period to a few weeks running from June to August 2011. The case later settled.
In Solomon-Shrawder v. CardioNet, Inc. (E.D. Pa. 2010), which Marc argued, the district court granted the motion to dismiss a putative class action alleging violations of the federal securities laws based on the company’s alleged response to an analyst report.
In In re GPC Biotech AG Sec. Litig. (S.D.N.Y. 2009), the district court granted a motion to dismiss a putative class action alleging violations of the federal securities laws based on the FDA’s decision not to approve a NDA.
In In re NutriSystem, Inc. Sec. Litig. (E.D. Pa. 2009), which Marc argued, the district court dismissed a putative class action alleging violations of the federal securities laws based on purportedly false and misleading statements about the company’s financial health in the face of competition from an anti-obesity drug.
In In re NutriSystem Derivative Litig. (E.D. Pa. 2009), which Marc argued, the district court granted the motion to dismiss a derivative suit based on alleged securities law violations.
Other Case-Dispositive Motions Granted by Trial Courts
In In re YRC Corp. Sec. Litig. (D. Kan. 2016), a putative class action alleging violations of the federal securities laws, the district court denied plaintiffs’ motion for class certification on adequacy grounds, ruling that both the proposed class representative and counsel were not adequate. Plaintiffs voluntarily dismissed the case.
In Hays v. Dvorak, (Del. Ch. 2015), which Marc argued, the Delaware Chancery Court granted a motion to stay a derivative case because the derivative suit relied on an adverse ruling in a patent trial, which ruling was on appeal. After the Federal Circuit vacated the bulk of the damages awarded in the patent trial, the Chancery Court approved the parties’ stipulation dismissing the case without prejudice.
Harvard Law School, 1971, J.D.
Swarthmore College, 1968, B.A.
District of Columbia
US Supreme Court
Clerkship to Judge Joseph Lord of the US District Court for the Eastern District of Pennsylvania (1972 - 1973)
Awards and Affiliations
Band 1, Litigation: Securities, Pennsylvania, Chambers USA (2018)
Band 1, Litigation: General Commercial, Pennsylvania, Chambers USA (2018)
Lifetime Achievement Award, The Legal Intelligencer (2017)
Life Sciences Star, Non-IP Litigation and Enforcement, LMG Life Sciences Guide (2017–2018)
Local Litigation Star, Commercial Litigation and Securities (Pennsylvania), Benchmark Litigation (2008–2018)
Recognized, Acritas Star Lawyer (2017)
Ranked, Chambers USA: America's Leading Lawyers for Business (2003–2017)
Recommended, Dispute Resolution: Securities Litigation - Defense, The Legal 500 US (2016-2018)
Recommended, Antitrust: Cartel and Antitrust - Civil Litigation/Class Actions, The Legal 500 US (2015)
Recommended, Litigation: Securities - Shareholder Litigation, The Legal 500 US (2014, 2015)
Recommended, Litigation, The Legal 500 US (2007)
Lawyer of the Year, Litigation – Securities, Philadelphia, The Best Lawyers in America (2013, 2019)
Recognized, Antitrust Law, Litigation: Securities, The Best Lawyers in America (2016–2019)
Recognized, Antitrust, The Best Lawyers in America (1995–2011)
Top 10, Pennsylvania Super Lawyers (2015)
Client Service All-Star, BTI Consulting Group (2013)
Securities MVP, Law360 (2012)
Recognized, Top 100 Philadelphia Lawyers
Recognized, Dispute Resolution, PLC Which Lawyer? Yearbook 2008
Wells Fargo Fidelity Award (2010)
Former President, Harvard Law School Association of Philadelphia