In re: The Boeing Company

USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 1 of 42 PUBLISHED UNITED STATES COURT OF APPEALS FOR THE FOURTH CIRCUIT No. 25-1492 STATE OF RHODE ISLAND OFFICE OF THE GENERAL TREASURER, on behalf of The Employees Retirement System of The State of Rhode Island; LOCAL #817 IBT PENSION FUND, Plaintiffs - Appellees, v. THE BOEING COMPANY; DAVID L. CALHOUN; DENNIS A. MUILENBURG; BRIAN J. WEST; GREGORY D. SMITH, Defendants - Appellants. ------------------------------ FORMER OFFICIALS OF THE U.S. SECURITIES AND EXCHANGE COMMISSION AND LAW PROFESSORS; THE SECURITIES INDUSTRY AND FINANCIAL MARKETS ASSOCIATION, Amici Supporting Appellants. Appeal from the United States District Court for the Eastern District of Virginia, at Alexandria. Leonie M. Brinkema, District Judge. (1:24-cv-00151-LMB-LRV) Argued: May 7, 2026 Decided: July 20, 2026 Before RICHARDSON, QUATTLEBAUM, and RUSHING, Circuit Judges. USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 2 of 42 Reversed and remanded by published opinion. Judge Quattlebaum wrote the opinion, in which Judge Richardson and Judge Rushing joined. ARGUED: Jeffrey Bryan Wall, GIBSON, DUNN & CRUTCHER LLP, Washington, D.C., for Appellants. Deepak Gupta, GUPTA WESSLER LLP, Washington, D.C., for Appellees. ON BRIEF: Benjamin L. Hatch, MCGUIREWOODS LLP, Washington, D.C.; Judson O. Littleton, Washington, D.C., Richard C. Pepperman II, Jacob E. Cohen, SULLIVAN & CROMWELL LLP, New York, New York, for Appellants. Carol C. Villegas, Christine M. Fox, Jake Edward Bissell-Linsk, LABATON KELLER SUCHAROW LLP, New York, New York; Gregory Beck, GUPTA WESSLER LLP, Washington, D.C.; Chad Johnson, Noam Mandel, Jonathan Zweig, Desiree Cummings, New York, New York, Douglas Wilens, ROBBINS GELLER RUDMAN & DOWD LLP, Boca Raton, Florida, for Appellees. Todd G. Cosenza, Brady Sullivan, Amanda M. Payne, WILLKIE FARR & GALLAGHER LLP, New York, New York, for Amici Former Officials of the United States Securities and Exchange Commission and Law Professors. Kevin M. Carroll, THE SECURITIES INDUSTRY AND FINANCIAL MARKETS ASSOCIATION, Washington, D.C.; Benjamin W. Snyder, Vladimir J. Semendyai, PAUL HASTINGS LLP, Washington, D.C., for Amicus The Securities Industry and Financial Markets Association. 2 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 3 of 42 QUATTLEBAUM, Circuit Judge: This appeal involves the requirements for class certification under Rule 23 of the Federal Rules of Civil Procedure. Certain shareholders of aerospace manufacturer The Boeing Company seek to hold that company and several of its former officers liable for violating Sections 10(b) and 20(a) of the Securities Exchange Act. In the plaintiffs’ view, Boeing repeatedly misrepresented its emphasis on safety in the wake of two deadly airplane crashes. These false and misleading statements, they contend, artificially inflated or maintained artificial inflation in Boeing’s stock price. The plaintiffs allege that a subsequent in-flight safety incident and disclosures revealed the truth—that Boeing wasn’t actually prioritizing safety. As a result, the artificial inflation dissipated, and the plaintiffs claim they suffered billions in losses. They seek to recover these losses as a class. For that to happen, the plaintiffs must first satisfy Rule 23. That rule operates as a procedural safeguard to balance the benefits of proceeding as a class—the primary one being the efficient resolution of numerous disputes that share common questions—with the cost of subjecting defendants to numerous individual claims of plaintiffs who may not have prosecuted claims on their own. Several Supreme Court decisions explain what plaintiffs must do to show class certification is appropriate and how district courts are to determine whether class certification is, in fact, merited under Rule 23. One of those decisions, Comcast Corp. v. Behrend, 569 U.S. 27 (2013), takes center stage in this appeal. Comcast concerns class damages. It requires plaintiffs, at the class- certification stage, to put forth evidentiary proof of a damages methodology showing how damages are calculable on a class-wide basis in a manner that is consistent with their theory 3 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 4 of 42 of liability and that is not speculative. Comcast also requires district courts to conduct a rigorous analysis to determine whether plaintiffs have satisfied this burden. Here, the district court certified a class after concluding that the plaintiffs satisfied Comcast and Rule 23. But the plaintiffs did not provide a damages methodology consistent with Comcast’s commands. And the district court did not conduct the rigorous analysis Comcast requires. So, the district court erred in certifying the class. We reverse and remand. I. BACKGROUND To frame the issues, we start with some basics on class actions before turning to plaintiffs’ factual allegations. 1 Then, we outline the procedural history of this case, describing both the motion-to-dismiss and class-certification proceedings below. A. Class Actions The way litigation traditionally works in the United States, a person or entity that claims to have been wronged must file a complaint, serve it on the alleged wrongdoer and then prosecute the case. Class actions, though, are different. Authorized under Rule 23, 2 a 1 The lead plaintiffs are the State of Rhode Island Office of the General Treasurer, on behalf of the Employees’ Retirement System of Rhode Island, and Local #817 IBT Pension Fund, associated with the International Brotherhood of Teamsters. 2 The modern class action lawsuit has roots in the English legal system. See 1 William B. Rubenstein, Newberg and Rubenstein on Class Actions § 1:12 (6th ed. 2026). Back in the day, there were two kinds of courts in England—common law courts and equity courts. See Missouri v. Jenkins, 515 U.S. 70, 127 (1995) (Thomas, J., concurring). Equity courts had a compulsory joinder rule. 1 Newberg and Rubenstein on Class Actions § 1:12. That meant anyone with a legal or beneficial interest in a lawsuit was required to be joined so a resolution would bind everyone. Id. But the compulsory joinder rule had problems. For instance, if not everyone with an interest could be joined, no relief could issue. Id. And if hundreds of parties were joined, administrative difficulties mounted. Id. So, the equity 4 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 5 of 42 class action is a “lawsuit in which the court authorizes a single person or a small group of people to represent the interests of a larger group.” Class Action, Black’s Law Dictionary (12th ed. 2024). In other words, a party does not have to file and prosecute their case to recover damages. If it is similar enough to other claims, a representative plaintiff can file the suit and prosecute it on behalf of the group. Class actions involve “a seemingly endless tug of pros and cons.” Stafford v. Bojangles’ Rests., Inc., 123 F.4th 671, 678 (4th Cir. 2024). “On the one hand, class actions offer the promise of resolving many similar suits at a single time.” Id. On the other hand, proceeding as a class implicates due process concerns—“absent class members’ grievances are litigated not directly by the class members themselves but by class representatives,” and “[d]efendants in those actions can be sued by a class of hundreds or thousands of people courts “resorted to a class, or representative, action by which one person could bring suit on behalf of others similarly situated that would be binding on the class.” Id. These bills of peace—as they were called—were available initially for accountings, declarations and injunctions. Id. It wasn’t until the merger of law and equity in 1873 that English courts approved class actions for damages. Id. The concept of an equitable representative action found its way into American jurisprudence. See, e.g., Smith v. Swomstedt, 57 U.S. (16 How.) 288, 298 (1853) (“The rule is well established that where the parties interested are numerous, and the suit is for an object common to them all, some of the body may maintain a bill on behalf of themselves and of the others . . . .”). Over here though, law and equity did not merge federally until the 1938 promulgation of the Federal Rules of Civil Procedure. See Fed. R. Civ. P. 2 advisory committee’s note to 1937 adoption; 1 Newberg and Rubenstein on Class Actions § 1:13. With that, the American class action for damages was born. See Montgomery Ward & Co. v. Langer, 168 F.2d 182, 187 (8th Cir. 1948) (“By Rule 23 the Supreme Court has extended the use of the class action device to the entire field of federal civil litigation by making it applicable to all civil actions.”); see also 1 Newberg and Rubenstein on Class Actions § 1:13; 7A Wright & Miller’s Federal Practice and Procedure § 1753 (4th ed. 2026). But it wasn’t until major changes were made to Rule 23 in 1966 that modern class action litigation took its present form. See 1 Newberg and Rubenstein on Class Actions § 1:16. 5 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 6 of 42 who are relieved of their normal responsibility to file and prosecute their own case.” Sharp Farms v. Speaks, 917 F.3d 276, 305 (4th Cir. 2019) (Quattlebaum, J., concurring). In addition, “class-action lawsuits can ratchet liability to potentially ruinous levels and force companies to settle or bet the store.” Stafford, 123 F.4th at 678. Rule 23 seeks to balance these interests. It “is a structural safeguard in our legal system developed to provide the benefits of class actions while simultaneously avoiding the risks associated with them.” Speaks, 917 F.3d at 305 (Quattlebaum, J., concurring); see also Stafford, 123 F.4th at 678. As a result, plaintiffs wishing to pursue a class action “must comply” with Rule 23. Stafford, 123 F.4th at 678. When they do, the district court may certify a class, allowing the class action to proceed. See Fed. R. Civ. P. 23(c)(1)(A). There are two categories of Rule 23 requirements plaintiffs must satisfy—those under Rule 23(a) and those under Rule 23(b). See Fed. R. Civ. P. 23(a)–(b). Rule 23(a) sets out four “[p]rerequisites” that every class action must meet—numerosity, commonality, typicality and adequacy of representation. Fed. R. Civ. P. 23(a)(1)–(4). 3 Rule 23(b) adds to these requirements, providing that a class action may only proceed if it falls into one of three different categories—(1) proceeding without a class would create inconsistencies or variance, be dispositive of non-class members’ interests or impair or impede these interests; (2) injunctive or declaratory relief is appropriate on a class-wide basis; or (3) common 3 The class must be “so numerous that joinder of all members is impractical,” there must be “questions of law or fact common to the class,” “the claims or defenses of the representative parties” must be “typical of the claims or defenses of the class” and “the representative parties” must “fairly and adequately protect the interests of the class.” Fed. R. Civ. P. 23(a)(1)–(4). 6 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 7 of 42 questions of law and fact predominate over individual questions and class adjudication is superior to individual adjudication. Fed. R. Civ. P. 23(b)(1)–(3). This case concerns whether class certification was proper under Rule 23(b)(3). This subsection allows a class to maintain an action if “the court finds that the questions of law or fact common to class members predominate over any questions affecting only individual members, and that a class action is superior to other available methods for fairly and efficiently adjudicating the controversy.” Fed. R. Civ. P. 23(b)(3). In this way, Rule 23(b)(3) seeks “to cover cases in which a class action would achieve economies of time, effort, and expense, and promote uniformity of decision as to persons similarly situated, without sacrificing procedural fairness or bringing about other undesirable results.” Amchem Prods., Inc. v. Windsor, 521 U.S. 591, 615 (1997) (citation modified). But a party proceeding under this subsection can’t just say so; it must actually satisfy its requirements. B. The Plaintiffs’ Allegations Boeing manufactures aircraft for civilian and military uses. 4 And it’s really only one of two commercial airplane builders. It and Airbus SE manufacture 99% of large 4 “When deciding a motion for class certification, a district court does not accept the plaintiff’s allegations in the complaint as true; rather, an evidentiary hearing is typically held on the certification issue.” Monroe v. City of Charlottesville, 579 F.3d 380, 384 (4th Cir. 2009). That’s because “Rule 23 holds plaintiffs to a higher bar than a pleading standard.” Stafford, 123 F.4th at 679. Plaintiffs “must present evidence that the putative class complies with Rule 23.” EQT Prod. Co. v. Adair, 764 F.3d 347, 357 (4th Cir. 2014). Even so, the parties relied extensively on the allegations in the plaintiffs’ amended complaint when describing the general background of this case. Memorandum in Support at 3–6, In re The Boeing Co. Sec. Litig., No. 1:24-cv-00151-LMB-LRV (E.D. Va. Dec. 13, 2024), ECF No. 104; Memorandum in Opposition at 6–9, In re The Boeing Co. Sec. Litig. (E.D. Va. Jan. 21, 2025), ECF No. 115. So, to frame the issues on appeal, we start from the 7 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 8 of 42 commercial airplanes. So, when Airbus announced the next generation of its A320 plane, the A320neo, in December 2010, Boeing felt pressure to keep up. To do so, Boeing decided to update its best-selling 737 model. It first delivered its new airplane—the 737 MAX—to customers in May 2017. In October 2018, Lion Air Flight JT 610, flying a Boeing 737 MAX, crashed shortly after takeoff, resulting in the loss of all on board. In March 2019, the same thing happened to Ethiopian Airlines Flight ET 302, flying another 737 MAX. That month, the Federal Aviation Administration grounded all 737 MAX airplanes. Investigations into these events uncovered a software issue. A defective sensor reported the planes’ noses were too high, which activated the planes’ Maneuvering Characteristics Augmentation System and drove their noses down. Congress got involved. The United States House of Representatives’ Committee on Transportation and Infrastructure determined, among other things, that costs, scheduling and other pressures at Boeing undermined the safety of the new aircraft and led to safety compromises. So did the Department of Justice and the Securities and Exchange Commission. On January 7, 2021, the DOJ and Boeing entered a three-year deferred prosecution agreement, which included a $2.5 billion settlement, to resolve a charge that Boeing conspired to defraud the FAA. And the SEC and Boeing later agreed to a $200 million settlement over allegations in the plaintiffs’ amended complaint. In doing so, we do not pass on the truth of these allegations. 8 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 9 of 42 allegations Boeing misled investors about the safety of its 737 MAX aircraft after the crashes. During this time, Airbus gained competitive ground. Its market share in the commercial aircraft market increased from 45.3% in 2018 to 62.5% in 2019. And Boeing’s revenues temporarily dipped at around that same time—from $101 billion in 2018 to $58.1 billion in 2020—before rebounding somewhat to $77.8 billion in 2023. Trying to turn things around, Boeing committed to improving the safety of its airplanes. For instance, in April 2019, it announced a board committee to examine safety and quality control policies. That September, Boeing adopted the committee’s recommendations in full, including the creation of a board committee on aerospace safety, a product and services safety organization and a design requirements program. Then, in January 2020, Boeing highlighted revisions to its codes of conduct, emphasizing that it expected its employees to report concerns and that it would not retaliate against those who did. Another announced change involved a practice called traveled work. Traveled work happens when an airplane needs to move down the assembly line so as to not hold up production but work on the plane at its current station on the line isn’t complete. To prevent delays, the plane moves down the line anyway, and incomplete work is completed, or repairs are made, later on. Boeing said it was eliminating traveled work because it negatively affected productivity and quality. Between January 7, 2021 and January 8, 2024, Boeing’s officers “repeatedly” made statements about safety. See, e.g., J.A. 81. These are the allegedly false and misleading 9 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 10 of 42 statements that form the basis of this lawsuit. According to the plaintiffs, there are 40 relevant statements that span three years in time. 5 We won’t list all of them here, but to provide a flavor for the various comments, here are a few examples—as categorized by the plaintiffs: 1. Statements about Safety and Quality in Manufacturing • March 5, 2021 – “Safety is, simply put, our highest priority. We are deeply committed to strengthening our safety processes through continuous improvement, learning and innovation.” J.A. 83. 6 • November 2, 2022 – “Safety dominates Boeing.” J.A. 84. 2. Statements about Boeing’s Culture and Encouraging Employees to Report Safety Concerns • March 3, 2023 – “We are working together to foster a culture of continuous improvement and enhance performance by creating an environment where employees are comfortable identifying gaps, seeking help and speaking up without fear of retaliation.” J.A. 88. 3. Statements about the Production of Safe Airplanes at a Stable and Growing Rate • July 28, 2021 – “Turning to our efforts to drive stability, with every action we are driving toward engineering excellence, production system stability, and first- time quality and delivery predictability while holding ourselves accountable to the highest standards.” J.A. 89. • April 27, 2022 – “On the supply side we are carefully managing supply chain constraints and working through issues as they arise to ensure the stability of our production system.” J.A. 90. 5 The plaintiffs alleged 75 misstatements between September 30, 2019 and April 5, 2024. These statements covered the class period proposed by the plaintiffs, which was to run from September 30, 2019 to May 14, 2024. But the district court certified a shorter class period, running from January 7, 2021 to January 8, 2024. Accordingly, our focus is on the alleged misstatements made during the certified class period. 6 We have omitted any emphasis added in each quoted statement. 10 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 11 of 42 4. Statements about Regulatory Compliance • January 31, 2022 – “We also are fully cooperating with U.S. government investigations related to the accidents and the 737 MAX, including an ongoing investigation by the Securities and Exchange Commission.” J.A. 92. According to the plaintiffs, these statements, and others like them, weren’t true. To explain why, they point to several whistleblowers. One whistleblower recounted how Boeing continued traveled work after the Lion Air and Ethiopian Airlines accidents, even though it said multiple times that it planned to eliminate that practice. Others described additional problems, including manufacturing shortcuts, unmet industry standards, airplane misalignment, improper quality control, work performed by unlicensed technicians, unimplemented safety improvements and continued retaliation against reporting employees. As the plaintiffs see it, the truth began to emerge on the night of Friday, January 5, 2024, when Alaska Airlines Flight 1282—flying a 737 MAX—made an emergency landing after a door plug in the plane’s fuselage detached minutes following takeoff. On the next day of trading, January 8, Boeing’s stock price dropped 8%. The loss of the door plug was caused in part by traveled work. Boeing had identified bad parts when the airplane’s fuselage arrived at Boeing’s manufacturing plant. Yet Boeing didn’t fix the issue when first noticed, so the 737 MAX went to the next station. When 11 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 12 of 42 Boeing made the necessary repairs 19 days later, workers did not replace four bolts on the door plug they opened. This was the door plug that blew off midflight. 7 C. The Plaintiffs’ Claims The plaintiffs’ allegations give rise to two claims under the Securities Exchange Act. The first claim alleges the defendants violated Section 10(b) and its accompanying regulation, Rule 10b–5. And the second claim asserts violations of Section 20(a) against the individual defendants. Section 10(b) and Rule 10b–5 “prohibit material misrepresentations and omissions in connection with the sale of securities.” Goldman Sachs Grp., Inc. v. Ark. Tchr. Ret. Sys., 594 U.S. 113, 117–18 (2021). 8 “Relatedly, section 20(a) is the vehicle for imposing liability 7 Between the evening of January 8 and May 14, 2024, the plaintiffs allege 21 additional drops in Boeing’s share price occurred following additional events related to the safety of the company’s airplanes. These events were wide-ranging—from United Airlines’ discovery of loose bolts on its 737 MAX airplanes, to the FAA halting 737 MAX production, to changes in Boeing’s leadership and beyond. Because the district court ended the class period after the alleged January 8, 2024 market correction which followed the Alaska Airlines incident, we won’t delve into the effect of these later corrective events. But the plaintiffs haven’t abandoned these events entirely. In the merits report submitted by their expert witness, economist Chad Coffman, the plaintiffs have attempted to revive five events that occurred after the class period ended. 8 Section 10(b) makes it unlawful “[t]o use or employ, in connection with the purchase or sale of any security registered on a national securities exchange . . . any manipulative or deceptive device or contrivance in contravention of such rules and regulations as the Commission may prescribe as necessary or appropriate in the public interest or for the protection of investors.” 15 U.S.C. § 78j(b). Rule 10b–5 makes it unlawful “[t]o make any untrue statement of a material fact or to omit to state a material fact necessary in order to make the statements made, in the light of the circumstances under which they were made, not misleading.” 17 C.F.R. § 240.10b–5(b). The Supreme Court has “inferred from these provisions an implied private cause of action permitting the recovery of damages for securities fraud.” Goldman Sachs, 594 U.S. at 118. 12 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 13 of 42 on control persons,” like officers. Singer v. Reali, 883 F.3d 425, 438 (4th Cir. 2018). “The liability of a control person under section 20(a) is derivative of—and dependent upon— liability of a controlled person under section 10(b).” Id. In other words, the plaintiffs’ success rises and falls with their Section 10(b) claim. Section 10(b) claims have six elements—“(1) a material misrepresentation or omission by the defendant; (2) scienter; (3) a connection between the misrepresentation or omission and the purchase or sale of a security; (4) reliance upon the misrepresentation or omission; (5) economic loss; and (6) loss causation.” Id. (quoting Stoneridge Inv. Partners, LLC v. Sci.-Atlanta, Inc., 552 U.S. 148, 157 (2008)). Here, the plaintiffs asserted their Section 10(b) claim in the form of a class action. They proposed a class period running from September 30, 2019—the date of the first allegedly false and misleading statement—until May 14, 2024—the date of the last alleged exposure. The plaintiffs identified dozens of purportedly material, false and misleading statements made by Boeing and its officers with the intent to deceive the investing public over three and a half years. They alleged they relied on all these statements when purchasing Boeing stock. 9 And they claimed these statements “artificially inflated and/or 9 The plaintiffs used the fraud-on-the-market theory to show reliance. That theory forms the basis of a rebuttable presumption of reliance established by the Supreme Court in Basic Inc. v. Levinson, 485 U.S. 224 (1988). “The ‘fundamental premise’ of the fraud- on-the-market theory underlying Basic’s presumption is ‘that an investor presumptively relies on a misrepresentation so long as it was reflected in the market price at the time of his transaction.’” Goldman Sachs, 594 U.S. at 118 (quoting Erica P. John Fund, Inc. v. Halliburton Co., 563 U.S. 804, 813 (2011)). And it’s a very important tool for plaintiffs in Section 10(b) class actions. As the Supreme Court has explained, “requiring proof of individualized reliance from each member of the proposed plaintiff class effectively would 13 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 14 of 42 artificially maintained” Boeing’s share price, causing them to lose money when the share price “declined as artificial inflation was removed from [the] share price” “[a]s truthful information was revealed to the market and/or as the previously undisclosed, understated, or misrepresented risks materialized.” J.A. 370. D. The Motion-to-Dismiss Proceedings Boeing moved to dismiss the amended complaint. According to Boeing, each allegedly false and misleading statement—which it said fell into one or more of six categories—wasn’t actionable. Memorandum in Support at 8–19, In re The Boeing Co. Sec. Litig., No. 1:24-cv-00151-LMB-LRV (E.D. Va. June 21, 2024), ECF No. 51. Boeing contended three categories of statements—(1) general statements about safety and quality; (2) aspirational statements in Boeing’s codes of conduct; and (3) statements concerning opinions, beliefs and future intentions—lacked materiality because they were too general and subjective. Id. at 10–15. The other three categories concerned statements about Boeing’s production and delivery, statements about disclosure of risk factors in SEC filings and statements the plaintiffs said limited the FAA’s recertification process for the 737 MAX to the Maneuvering Characteristics Augmentation System when it really involved not only that system but also additional airplane features. Id. at 15–19. In Boeing’s view, prevent such plaintiffs from proceeding with a class action, since individual issues would overwhelm the common ones.” Halliburton, 563 U.S. at 810 (citation modified). True, the fraud-on-the-market theory also derives from the notion that requiring individual proof of reliance in a Section 10(b) case “would place an unnecessarily unrealistic evidentiary burden on the Rule 10b–5 plaintiff who has traded on an impersonal market.” Id. (quoting Basic, 485 U.S. at 245). But the result is that, in part, the elements of a Section 10(b) claim are altered to increase the ability to achieve class certification. While that might seem odd, current precedent allows it. 14 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 15 of 42 these statements weren’t actionable because it hadn’t said anything false or misleading about its production and delivery, the plaintiffs hadn’t explained why its SEC disclosures were false and misleading with particularity and its statements never limited the FAA recertification process, among other reasons. Id. In response, the plaintiffs stressed that while aspirational puffery and opinion often don’t meet the materiality requirement of a Section 10(b) claim, some courts have found that such statements can in contexts like the airline industry, where safety is paramount, or when made to reassure investors. And they emphasized repetition may make otherwise immaterial statements material. Then, the plaintiffs addressed each of Boeing’s six categories of purportedly immaterial statements, insisting each statement in those categories was material. The district court addressed Boeing’s motion during a hearing. It denied the motion without argument after stating only that it thought the “extensive amount of detail” in the amended complaint “adequately hit[] all the necessary requirements to let the case go forward,” including “that there ha[d] been material misstatements made to the investing public.” J.A. 519. 10 E. The Class-Certification Proceedings Having survived Boeing’s motion to dismiss, the plaintiffs moved to certify a class. In their motion, they described their class claims as based on a single course of conduct by 10 The district court’s motion-to-dismiss order isn’t appealable at this stage of the litigation, so we don’t address it. We only note it for its relevance to issues properly before us on appeal. 15 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 16 of 42 Boeing—the making of false and misleading statements which caused Boeing’s stock to trade at artificially high levels. Memorandum in Support at 15, In re The Boeing Co. Sec. Litig. (E.D. Va. Dec. 13, 2024), ECF No. 104. The plaintiffs said Boeing’s “many misstatements artificially inflated and artificially maintained the price of Boeing’s stock.” Id. at 2; see also id. at 9 (noting common questions included “whether, and to what extent, the market price of Boeing common stock was artificially inflated or maintained during the Class Period”). According to the plaintiffs, this inflation dissipated when the Alaska Airlines incident and other corrective events revealed the truth. Id. at 2. On the issue of damages, the plaintiffs pointed to Comcast as setting the proper standard. Id. at 27. They argued they satisfied Comcast by invoking “the ‘out of pocket’ methodology” provided by an economist, Chad Coffman. Id. 11 The plaintiffs contended “[t]his approach matche[d] [their] theory of liability.” Id. Coffman offered his damages methodology in a report filed with the plaintiffs’ motion for class certification. Its damages discussion was brief—just a few pages. Coffman said the out-of-pocket methodology was the “standard and well-accepted method for calculating class-wide damages in cases under Section 10(b) of the Exchange Act.” J.A. 589. Under this approach, each class member’s “damages are equal to the artificial inflation per share at the time of purchase minus the artificial inflation per share at the time of sale 11 Coffman, a chartered financial analyst, holds a bachelor’s degree in economics and a master’s degree in public policy. His work includes “analyzing how securities prices react to new information and evaluating damages in securities-related matters.” J.A. 546. 16 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 17 of 42 (or if the share is not sold prior to the full revelation of the fraud, just the artificial inflation at the time of purchase).” J.A. 589–90. Coffman described the out-of-pocket calculation as requiring two types of inputs. One involved each class member’s purchase and sale histories. The other was artificial inflation per share per day, which he planned to calculate via “a detailed loss causation analysis.” J.A. 590. But he said any method for doing so would be common to the class. Still, Coffman summarized how he might go about determining artificial inflation. He explained he might start with “an event study that measures price reactions to disclosures that revealed the relevant truth, such as the price reaction to events such as the Alaska Airlines Incident that exposed systemic and pervasive manufacturing safety and quality deficiencies at Boeing.” J.A. 591. This approach, if followed, would require “disaggregating the price impact of corrective disclosures from confounding information”—in other words, excluding any decrease in the stock price not related to the alleged misstatements. J.A. 591. And he provided a non-exhaustive list of potential valuation approaches that he might use to achieve this. Coffman also noted his analysis would need to show how artificial inflation changed over time. He gave three possible ways to do that. He could use “‘constant dollar inflation,’ which implies that the artificial inflation was the same dollar amount during the class period.” J.A. 592. Or he could use “‘constant percentage inflation,’ which implies the price was inflated by a consistent percentage in the absence of additional disclosures.” J.A. 592. Or a third “approach may be necessary, such as where the artificial inflation has evolved based upon the nature and timing of specific misstatements or the inflation varied on a 17 USCA4 Appeal: 25-1492 Doc: 87 Filed: 07/20/2026 Pg: 18 of 42 daily basis as a result of information contained in internal documents obtained in discovery.” J.A. 592. Boeing opposed class certification. Memorandum in Opposition, In re The Boeing Co. Sec. Litig. (E.D. Va. Jan. 21, 2025), ECF No. 115. It contended principally that Coffman’s proposed damages methodology did not meet Comcast’s requirements. Id. at 10–24. As Boeing saw it, Coffman had proposed no methodology at all—he had merely identified possible techniques that he might use to calculate damages without committing to an approach. Id. at 11–12. Nor did Coffman provide any detail about how he would account for the complexity of the case—involving numerous allegedly false and misleading statements, of varying kinds, made over the course of years in a changing environment. Id. at 14–19. Boeing also argued Coffman’s report didn’t demonstrate how his proposed damages methodology was consistent with the plaintiffs’ liability theory. Id. at 19–21. According to Boeing, to overcome the materiality problems with their alleged misstatements, the plaintiffs advanced a materiality-by-repetition theory—the materiality of the allegedly false and misleading statements crept in over time and, with it, so did artificial inflation. Id. at 4, 19–21. But Boeing argued that using a constant measure of inflation, lik