class certification

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The following guest post examines the resolution of class certification motions in securities class action lawsuits during 2025; considers the parties’ economic arguments in support of or in opposition to class certification; and analyzes the courts evaluation of those arguments. The article is written by Andrew Roper, Mame Maloney, Brendan Rudolph, and Ravi Sinha, Principals at The Brattle Group, and Aidan Kutner, an Associate at The Brattle Group. We would like to thank the authors for allowing us to publish their article as a guest post on our site. Here is the authors’ article.

Continue Reading Guest Post: Key Trends in 2025 Class Certification Decisions: Fraud-on-the-Market Under Fire
Doug Greene

In the following guest post, Doug Greene, Partner at the BakerHostetler law firm and Chair of the firm’s Securities and Governance Litigation Team, takes a look at the growing problems with the defense of securities litigation, including skyrocketing defense costs, and proposes some solutions to these problems. A version of this article previously was published on The D&O Discourse blog. I would like to thank Doug for allowing me to publish his article as a guest post on this site. I welcome guest post submissions from responsible authors on topics of interest to this site’s readers. Please contact me directly if you would like to submit a guest post. Here is Doug’s article.

Continue Reading Guest Post: The Future of Securities Litigation Defense
Sarah Abrams

Securities class action lawsuits in the U.S. are very much subject to the rules of civil procedure regarding class action certification. In the following guest post, Sarah Abrams, Head of Claims Baleen Specialty, a division of Bowhead Specialty, examines a recent district court class action certification decision and considers its implication. I would like to thank Sarah for allowing me to publish her article as a guest post on this site. I welcome guest post submissions from responsible authors on topics of interest to this site’s readers. Please contact me directly if you would like to submit a guest post. Here is Sarah’s article.

Continue Reading Failure to Launch

Matthew L. Mustokoff

Margaret E. Mazzeo

Since the U.S. Supreme Court’s 2014 decision in Halliburton II, the lower courts have wrestled with questions on how to address the “price impact” of corrective disclosures. In the following guest post, Matthew L. Mustokoff and Margaret E. Mazzeo, partners at the Kessler Topaz Meltzer & Check LLP law firm, examine several critical unanswered questions concerning price impact. I would like to thank Matt and Margaret for allowing me to publish their article as a guest post on this site. I welcome guest post submissions from responsible authors on topics of interest to this blog’s readers. Please contact me directly if you would like to submit a guest post. Here is the authors’ article.
Continue Reading Guest Post: Price Impact, the Speed of Information, and Securities Class Certification

Daniel J. Tyukody

Robert A. Horowitz

Ever since the U.S. Supreme Court’s March 2010 decision in Morrison v. National Australia Bank courts have struggled with application of the Morrison Court’s standard to securities lawsuits involving transactions in American Depository Receipts. As I noted in a prior blog post, one of the latest court rulings involving the application of Morrison to ADR transactions was the denial of the motion for class certification in the Toshiba case. In the following guest post, Daniel J. Tyukody and Robert A. Horowitz take a closer look that the class certification motion denial in Toshiba and consider the implications of the ruling.  Tyukody and Horowitz are Co-Chairs of Greenberg Traurig, LLP’s Securities Litigation Practice. I would like to thank the authors for allowing me to publish their article as a guest post on this site. I welcome guest post submissions from responsible authors on topics of interest to this blog’s readers. Here is the authors’ article.
Continue Reading Guest Post: The Elusive Search For Determining The Reach Of Section 10(b) Liability Following Morrison

In its June 21, 2021 decision in Goldman Sachs Group, Inc. v. Arkansas Teacher Retirement System (discussed here), the U.S. Supreme Court provided important guidance regarding price impact evidence at the class certification stage of securities class action litigation. In the following guest post, Nessim Mezrahi, Stephen Sigrist, and Carolina Doherty discuss class certification implications of price impact in securities class actions pursuant to the Goldman Sachs decision. Mezrahi is cofounder and CEO, Sigrist is VP of data science, and Doherty is VP of business development at SAR. A version of this article previously was published in Law360. I would like to thank the authors for allowing me to publish their article as a guest post on this site. I welcome guest post submissions from responsible authors on topics of interest to this blog’s readers. Please contact me directly if you would like to submit a guest post. Here is the authors’ article.
Continue Reading Guest Post: Q2 Stock Drop Stats Buoy High Court’s Goldman Ruling

When the U.S. Supreme Court granted the petition for a writ of certiorari to take up class certification questions raised in the long-running Goldman Sachs securities class action lawsuit, some commentators thought the case might give the Court the opportunity to reconsider fundamental issues about the presumption of reliance under the “fraud on the market” theory in connection with class certification in securities suits. However, as the case has turned out, the Court’s consideration of the case has not produced any fundamental recasting of any key issues; instead, the Court on June 21, 2021 issued a narrow decision that the majority opinion itself acknowledged, with respect to the most significant substantive part of the Court’s opinion, will not be “outcome determinative” in many cases. The Court’s June 21, 2021 decision can be found here.
Continue Reading Supreme Court Vacates Class Certification in Goldman Sachs Securities Suit on Narrow Grounds

Nessim Mezrahi

Stephen Sigrist

In the following guest post, Nessim Mezrahi and Stephen Sigrist discuss their analysis of Rule 10b-5 private securities fraud litigation in 2019 and 2020 against U.S. Issuers, and the impact of recent guidance by the 2nd and 7th Circuits on Halliburton II stock price impact defenses at the class certification stage.  Mezrahi is cofounder and CEO and Sigrist is a data scientist at SAR.  SAR’s January 8, 2021 press release discussing a more detailed 4Q 2020 securities class action analysis can be found here. A version of this article previously was published on Law360. I would like to thank Nessim and Stephen for allowing me to publish their article as a guest post on this site. I welcome guest post submissions from responsible authors on topics of interest to this blog’s readers. Please contact me directly if you would like to submit a guest post. Here is the authors’ article.
Continue Reading Guest Post: Halliburton II Price Impact Defenses Can Limit Severity on Deficient Exchange Act Claims

In the same December 11, 2020 Order in which it rejected the bid by the Texas Attorney General to overturn the results of the 2020 Presidential election, the U.S. Supreme Court also agreed to take up a case involving the effort of Goldman Sachs to overturn the certification of a class in the long-running securities lawsuit. The case relates to the bank’s alleged conflicts of interest in structuring collateralized debt obligation securities before the global financial crisis. The case will require the Court to address important questions pertaining to the ability of securities lawsuit defendants opposing class certification to attempt to rebut the presumption of reliance and the extent to which the defendants in opposing class certification can rely on matter that is also relevant to merits-related issues such as materiality.
Continue Reading U.S. Supreme Court Agrees to Take Up Securities Suit Class Certification Issues

Tim Hoeffner

Paul Ferrillo

The Second Circuit issued its latest decision in the long running Goldman Sachs Group securities class action litigation on April 7, 2020 (here). In the following guest post, Tim Hoeffner and Paul Ferrillo of the McDermott, Will & Emery law firm take a look at the Second Circuit’s decision and analyze its implications. I would like to thank Tim and Paul for allowing me to publish their article as a guest post on this site. I welcome guest post submissions from responsible authors on topics of interest to this blog’s readers. Please contact me directly if you would like to submit a guest post. Here is Time and Paul’s article.
Continue Reading Guest Post: Close Call in New Second Circuit Class Certification Decision