Full opinion text
NAOMI REICE BUCHWALD, UNITED STATES DISTRICT JUDGE LIBOR V I I Table of Contents I. Introduction ...457 II. General Legal Standards ...458 1. Class Certification ...458 1.1. Standing ...458 1.2. Rule 23(a) ...459 1.3. Rule 23 (b) (3) ...461 1.4. Ascertainability ...463 1.5. Modifications to the Class Definition ...463 2. Expert Opinion ...465 2.1. The Daubert Standard ...465 2.2. Application at Class Certification ...470 III. Exchange-Based Action ...471 1. Rabobank's Daubert Motions ...473 1.1. Dr. Seyhun ...473 1.2. Dr. Netz....489 1.3. Mr. Beevers ...496 1.4. Mr. Miller ...508 2. Exchange Plaintiffs' Daubert Motions ...510 2.1. Dr. Culp ...510 2.2. Dr. Hubbard ...515 2.3. Dr. Willig ...518 3. Trader-Based Manipulation Class ...528 3.1. "Fail-Safe" Class Definition ...528 3.2. Standing ...530 3.3. Ascertainability ...533 3.4. Rule 23(a) ...533 3.5. Predominance ...539 3.6. Superiority ...544 3.7. Modification of the Class Definition ...546 3.8. Conclusion ...548 4. Suppression Class ...548 4.1. Class Definition ...548 4.2. Ascertainability ...549 4.3. Rule 23(a) ...549 4.4. Predominance ...551 4.5. Superiority ...555 4.6. Conclusion ...555 IV. Lender Action ...556 1. Daubert Motions ...556 1.1. Dr. Webb ...557 1.2. Dr. Willig ...560 2. Class Certification ...563 2.1. Rule 23(a) ...563 2.2. Ascertainability ...569 2.3. Predominance ...569 2.4. Superiority ...579 2.5. Conclusion ...580 V. OTC Action ...581 1. Daubert Motion against Dr. Stiglitz ...583 2. Class Certification ...584 2.1. Standing ...584 2.2. Rule 23(a) ...585 2.3. Predominance ...590 2.4. Modification of the Class Definition ...602 2.5. Superiority ...607 2.6. Conclusion ...607 VI. Interlocutory Appealability ...608 VII. Conclusion ...609 I. INTRODUCTION After more than six years of litigation and six substantial opinions considering extensively the nature of LIBOR and its alleged manipulation, we consider in this, our seventh major opinion, whether three of the cases consolidated into this multidistrict litigation should proceed as class actions: the Exchange-Based action, Metzler Investment GmbH v. Credit Suisse Group AG, No. 11 Civ. 2613; the Lender action, Berkshire Bank v. Bank of America Corp., No. 12 Civ. 5723; and the Over-the-Counter (OTC) action, Mayor of Baltimore v. Credit Suisse Group AG, No. 11 Civ. 5450. For the reasons stated below, Exchange plaintiffs' and Berkshire Bank's motions for certification of an Exchange-based class and a Lender class are denied. We grant in part and deny in part OTC plaintiffs' motion, certifying a class only as to the antitrust claims in that action. In litigating the question of class certification, the parties have also filed ten motions to exclude expert testimony under the admissibility standards set forth in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993). The only one-line summary we can provide is that some of the Daubert motions are granted, some are denied, and others are granted in part and denied in part, as set forth in extensive detail below. II. GENERAL LEGAL STANDARDS We first set forth the general legal standards applicable to our resolution of the pending motions. 1. Class Certification "The class action is 'an exception to the usual rule that litigation is conducted by and on behalf of the individual named parties only.' " Wal-Mart Stores, Inc. v. Dukes, 564 U.S. 338, 348, 131 S.Ct. 2541, 180 L.Ed.2d 374 (2011) (quoting Califano v. Yamasaki, 442 U.S. 682, 700-01, 99 S.Ct. 2545, 61 L.Ed.2d 176 (1979) ). "To come within the exception, a party seeking to maintain a class action 'must affirmatively demonstrate his compliance' with Rule 23." Comcast Corp. v. Behrend, 569 U.S. 27, 33, 133 S.Ct. 1426, 185 L.Ed.2d 515 (2013) (quoting Dukes, 564 U.S. at 350, 131 S.Ct. 2541 ). When presented with a motion for class certification, we are to "assess all of the relevant evidence admitted at the class certification stage and determine whether each Rule 23 requirement has been met, just as [we] would resolve a dispute about any other threshold prerequisite for continuing a lawsuit." In re Initial Pub. Offerings Sec. Litig. ("In re IPO"), 471 F.3d 24, 42 (2d Cir. 2006). This assessment necessarily entails the resolution of "factual disputes relevant to each Rule 23 requirement," an obligation that "is not lessened by overlap between a Rule 23 requirement and a merits issue, even a merits issue that is identical with a Rule 23 requirement." Id. at 41 ; see also Dukes, 564 U.S. at 351, 131 S.Ct. 2541 (noting that the "rigorous analysis" of the Rule 23 requirements "will entail some overlap with the merits of the plaintiff's underlying claim"). "[T]he preponderance of the evidence standard applies to evidence proffered to establish Rule 23's requirements." Teamsters Local 445 Freight Div. Pension Fund v. Bombardier Inc., 546 F.3d 196, 202 (2d Cir. 2008). 1.1. Standing Before considering the Rule 23 requirements, we first consider threshold standing issues. "Standing" in the class action context refers to two related but analytically distinct doctrines separated by a "murky line": "traditional Article III standing" on the one hand and "so-called 'class standing' " on the other. Ret. Bd. of the Policemen's Annuity & Benefit Fund v. Bank of N.Y. Mellon ("RBPA"), 775 F.3d 154, 160 (2d Cir. 2014) ; see also LIBOR III, 27 F.Supp.3d at 480-82. Article III standing is assessed using the oft-recited three-part formulation set forth by the Supreme Court: a "plaintiff must have (1) suffered an injury in fact, (2) that is fairly traceable to the challenged conduct of the defendant, and (3) that is likely to be redressed by a favorable judicial decision." Spokeo, Inc. v. Robins, --- U.S. ----, 136 S.Ct. 1540, 1547, 194 L.Ed.2d 635 (2016) ; see also LIBOR III, 27 F.Supp.3d at 481 (citing Lujan v. Defs. of Wildlife, 504 U.S. 555, 560-61, 112 S.Ct. 2130, 119 L.Ed.2d 351 (1992) ). While an injury-in-fact must be "concrete and particularized" and "actual or imminent," Lujan, 504 U.S. at 560, 112 S.Ct. 2130, "an injury-in-fact need not be capable of sustaining a valid cause of action," Denney v. Deutsche Bank AG, 443 F.3d 253, 264 (2d Cir. 2006). Rather, "the fact that an injury may be outweighed by other benefits, while often sufficient to defeat a claim for damages, does not negate [Article III] standing." Id. at 265. In the class action context, the Second Circuit has made clear that "no class may be certified that contains members lacking Article III standing" and that any "class must therefore be defined in such a way that anyone within it would have [Article III] standing." Id. at 264. However, when presented with a putative class, "[w]e do not require that each member ... submit evidence of personal standing." Id. at 263. Rather, "only one of the named Plaintiffs is required to establish standing in order to seek relief on behalf of the entire class." Cent. States Se. & Sw. Areas Health & Welfare Fund v. Merck-Medco Managed Care, L.L.C., 504 F.3d 229, 241 (2d Cir. 2007) (emphasis added). "[P]assive members need not make any individual showing of standing, because the standing issue focuses on whether the plaintiff is properly before the court, not whether represented parties or absent class members are properly before the court." Denney, 443 F.3d at 264 (alteration in original) (quoting 1 Herbert B. Newberg & Alba Conte, Newberg on Class Actions § 2:7 (4th ed. 2002) ). While only one named plaintiff need establish Article III standing and our analysis need not consider evidence from absent class members, we must nonetheless consider Article III standing as against each defendant. "[F]or every named defendant there must be at least one named plaintiff who can assert a claim directly against that defendant." LIBOR III, 27 F.Supp.3d at 481 (emphasis omitted) (quoting NECA-IBEW Health & Welfare Fund v. Goldman Sachs & Co. ("NECA"), 693 F.3d 145, 159 (2d Cir. 2012) ). "[A]t that point, [Article III] standing is satisfied and only then will the inquiry shift to a class action analysis" and the question of class standing, which refers to a named plaintiff's ability to assert claims on behalf of absent class members. NECA, 693 F.3d at 159 (quoting Merck-Medco, 504 F.3d at 241 ). "[I]n a putative class action, a plaintiff has class standing if he plausibly alleges (1) that he personally has suffered some actual injury as a result of the putatively illegal conduct of the defendant, and (2) that such conduct implicates the same set of concerns as the conduct alleged to have caused injury to other members of the putative class by the same defendants." RBPA, 775 F.3d at 161 (emphasis added) (alteration in original) (quoting NECA, 693 F.3d at 162 ). This standard, "derive[d] from constitutional standing principles" but also distinct from Article III standing itself, serves to insure that "the named plaintiff's litigation incentives are sufficiently aligned with those of the absent class members that the named plaintiff may properly assert claims on their behalf." Id. As the Second Circuit's formulation of the class standing test makes clear, class standing is assessed based on allegations rather than evidence. See, e.g., id. (holding that named plaintiffs had satisfied the first prong of the two-prong class standing test because "they ha[d] adequately pled that they have personally suffered an actual injury as a result of [the defendant's] putatively illegal conduct"). 1.2. Rule 23(a) To proceed as a class action, each of the requirements of Rule 23(a) must be met. As relevant here, Rule 23(a) provides that "[o]ne or more members of a class may sue ... as representative parties on behalf of all members only if: (1) the class is so numerous that joinder of all members is impracticable; (2) there are questions of law or fact common to the class; (3) the claims ... of the representative parties are typical of the claims ... of the class; and (4) the representative parties will fairly and adequately protect the interests of the class." Fed. R. Civ. P. 23(a). These requirements are generally referred to as numerosity, commonality, typicality, and adequacy of representation. Rule 23(a)(1) requires the class to be sufficiently numerous such that "joinder of all members is impracticable," Fed. R. Civ. P. 23(a)(1), but this requirement "does not mandate that joinder of all parties be impossible," Merck-Medco, 504 F.3d at 244. Though "the numerosity inquiry is not strictly mathematical," numerosity "is presumed for classes larger than forty members." Pa. Pub. Sch. Emps.' Ret. Sys. v. Morgan Stanley & Co., 772 F.3d 111, 120 (2d Cir. 2014). Plaintiffs need not furnish "evidence of exact class size or identity of class members to satisfy the numerosity requirement." Robidoux v. Celani, 987 F.2d 931, 935 (2d Cir. 1993). The next requirement, commonality, demands that there be "questions of law or fact common to the class." Fed. R. Civ. P. 23(a)(2). A question is common to the class if it is "capable of classwide resolution-which means that determination of its truth or falsity will resolve an issue that is central to the validity of each one of the claims in one stroke." Dukes, 564 U.S. at 350, 131 S.Ct. 2541. That is, "[c]ommonality requires the plaintiff to demonstrate that the class members 'have suffered the same injury,' " which requires establishing more than the mere fact that class members "have all suffered a violation of the same provision of law." Id. at 349-50, 131 S.Ct. 2541 (quoting Gen. Tel. Co. of the Sw. v. Falcon, 457 U.S. 147, 157, 102 S.Ct. 2364, 72 L.Ed.2d 740 (1982) ). However, "[w]here the same conduct or practice by the same defendant gives rise to the same kind of claims from all class members, there is a common question." Johnson v. Nextel Commc'ns, Inc., 780 F.3d 128, 137 (2d Cir. 2015) (quoting Suchanek v. Sturm Foods, Inc., 764 F.3d 750, 756 (7th Cir. 2014) ). Third, "[t]o establish typicality under Rule 23(a)(3), the party seeking certification must show that 'each class member's claim arises from the same course of events and each class member makes similar legal arguments to prove the defendant's liability.' " In re Flag Telecom Holdings, Ltd. Sec. Litig., 574 F.3d 29, 35 (2d Cir. 2009) (quoting Robidoux, 987 F.2d at 936 ). This requirement is related to, but distinct from, the requirement of class standing. See RBPA, 775 F.3d at 161 (citing NECA, 693 F.3d at 158 n.9 ). "Typicality requires that 'the disputed issue[s] of law or fact occupy essentially the same degree of centrality to the named plaintiff's claim as to that of other members of the proposed class.' " Mazzei v. Money Store, 829 F.3d 260, 272 (2d Cir. 2016) (internal quotation marks omitted) (quoting Caridad v. Metro-N. Commuter R.R., 191 F.3d 283, 293 (2d Cir. 1999), overruled on other grounds by In re IPO, 471 F.3d 24 ). Accordingly, typicality is not satisfied "where a putative class representative is subject to unique defenses which threaten to become the focus of the litigation." Baffa v. Donaldson, Lufkin & Jenrette Sec. Corp., 222 F.3d 52, 59 (2d Cir. 2000) (quoting Gary Plastic Packaging Corp. v. Merrill Lynch, Pierce, Fenner & Smith, Inc., 903 F.2d 176, 180 (2d Cir. 1990) ). "[T]he defendant need not show at the certification stage that [a] unique defense will prevail, only that it is meritorious enough to require the plaintiff to devote considerable time to rebut the unique defense," In re Digital Music Antitrust Litig., 321 F.R.D. 64, 97 (S.D.N.Y. 2017) (quoting Lapin v. Goldman Sachs & Co., 254 F.R.D. 168, 179 (S.D.N.Y. 2008) ). "However, the court should not disqualify a named plaintiff based upon any groundless, far-fetched defense that the defendant manages to articulate." Lapin, 254 F.R.D. at 179 (quoting Hallet v. Li & Fung, Ltd., No. 95 Civ. 8917 (JSM), 1997 WL 621111, at *3 (S.D.N.Y. Oct. 6, 1997) ). Finally, "the representative parties [must] fairly and adequately protect the interests of the class." Fed. R. Civ. P. 23(a)(4). This requirement overlaps in part with those of commonality and typicality, but adequacy of representation "also raises concerns about the competency of class counsel and conflicts of interest." Dukes, 564 U.S. at 349 n.5, 131 S.Ct. 2541 (quoting Falcon, 457 U.S. at 158 n.13, 102 S.Ct. 2364 ); see also Baffa, 222 F.3d at 60 ("Generally, adequacy of representation entails inquiry as to whether: 1) plaintiff's interests are antagonistic to the interest of other members of the class and 2) plaintiff's attorneys are qualified, experienced and able to conduct the litigation."). Accordingly, an analysis of adequacy of representation considers "whether the class representative has adequate incentive to pursue the class's claim, and whether some difference between the class representative and some class members might undermine that incentive." In re Payment Card Interchange Fee & Merch. Disc. Antitrust Litig., 827 F.3d 223, 231 (2d Cir. 2016). However, "[n]ot every conflict among subgroups of a class will prevent class certification-the conflict must be 'fundamental' to violate Rule 23(a)(4)." In re Literary Works in Elec. Databases Copyright Litig., 654 F.3d 242, 249 (2d Cir. 2011). 1.3. Rule 23(b)(3) In addition to satisfying each requirement of Rule 23(a), a putative class must also meet "[o]ne of the bases for certification under Rule 23(b)." Roach v. T.L. Cannon Corp., 778 F.3d 401, 405 (2d Cir. 2015). Each class of plaintiffs here seeks to proceed under Rule 23(b)(3), which provides that a class action may proceed as such 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) (emphasis added). Predominance and superiority must each be satisfied. See Sykes v. Mel S. Harris & Assocs., 780 F.3d 70, 82 (2d Cir. 2015) (referring to Rule 23(b)(3) as a "disjunctive inquiry"); see also Roach, 778 F.3d at 405. "The Rule 23(b) (3) predominance inquiry tests whether proposed classes are sufficiently cohesive to warrant adjudication by representation." Amchem Prods., Inc. v. Windsor, 521 U.S. 591, 623, 117 S.Ct. 2231, 138 L.Ed.2d 689 (1997). It serves to "ensure [ ] that the class will be certified only when it 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.' " Cordes & Co. Fin. Servs., Inc. v. A.G. Edwards & Sons, Inc., 502 F.3d 91, 104 (2d Cir. 2007) (omission in original) (quoting Amchem, 521 U.S. at 615, 117 S.Ct. 2231 ). The predominance analysis entails "careful scrutiny to the relation between common and individual questions in a case." Tyson Foods, Inc. v. Bouaphakeo, --- U.S. ----, 136 S.Ct. 1036, 1045, 194 L.Ed.2d 124 (2016). "An individual question is one where 'members of a proposed class will need to present evidence that varies from member to member,' while a common question is one where 'the same evidence will suffice for each member to make a prima facie showing [or] the issue is susceptible to generalized, class-wide proof.' " Id. (alterations in original) (quoting 2 William B. Rubenstein, Newberg on Class Actions § 4:50 (5th ed. 2012) ). As its name suggests, "[t]he predominance requirement calls only for predominance, not exclusivity, of common questions." In re Visa Check/MasterMoney Antitrust Litig., 280 F.3d 124, 140 (2d Cir. 2001) (quoting In re Alcoholic Beverages Litig., 95 F.R.D. 321, 328 (E.D.N.Y. 1982) ), overruled on other grounds by In re IPO, 471 F.3d 24. The inquiry is inherently comparative, taking into account the weight and significance of common and individual issues rather than simply their numbers. See, e.g., In re Petrobras Sec., 862 F.3d 250, 268 (2d Cir. 2017) ("[P]redominance is a comparative standard."). The existence of a single common question suffices to establish commonality, but " Rule 23(b)(3)'s predominance requirement is 'more demanding than Rule 23(a).' " Nextel, 780 F.3d at 138 (quoting Comcast, 569 U.S. at 34, 133 S.Ct. 1426 )). Ultimately, we ask "whether issues susceptible to generalized proof outweigh individual issues," Sykes, 780 F.3d at 88 (internal quotation marks omitted) (quoting McLaughlin v. Am. Tobacco Co., 522 F.3d 215, 231 (2d Cir. 2008), abrogated on other grounds by Bridge v. Phx. Bond & Indem. Co., 553 U.S. 639, 128 S.Ct. 2131, 170 L.Ed.2d 1012 (2008) ), or put differently, whether "common issues are 'more substantial' than individual ones," Myers v. Hertz Corp., 624 F.3d 537, 549 (2d Cir. 2010) (quoting Moore v. PaineWebber, Inc., 306 F.3d 1247, 1252 (2d Cir. 2002) ). In conducting this balancing test, we "assess (1) the 'elements of the claims and defenses to be litigated,' and (2) 'whether generalized evidence could be offered to prove those elements on a class-wide basis or whether individualized proof will be needed to establish each class member's entitlement to relief.' " Nextel, 780 F.3d at 138 (quoting 1 McLaughlin on Class Actions § 5:23 (11th ed. 2014) ); see also Erica P. John Fund, Inc. v. Halliburton Co. ("Halliburton I"), 563 U.S. 804, 809, 131 S.Ct. 2179, 180 L.Ed.2d 24 (2011) ("Considering whether 'questions of law or fact common to class members predominate' begins, of course, with the elements of the underlying cause of action." (quoting Fed. R. Civ. P. 23(b)(3) )). "This analysis is 'more[ ] qualitative than quantitative,' and must account for 'the nature and significance of the material common and individual issues in the case.' " In re Petrobras, 862 F.3d at 271 (alterations in original) (citations omitted) (quoting 1 William B. Rubenstein, Newberg on Class Actions § 4:50 (5th ed. 2012) ). In addition to establishing the predominance of common questions, plaintiffs must also establish "that a class action is superior to other available methods for fairly and efficiently adjudicating the controversy." Fed. R. Civ. P. 23(b)(3). Rule 23(b)(3) sets forth four "matters pertinent" to the superiority inquiry: "(A) the class members' interests in individually controlling the prosecution or defense of separate actions; (B) the extent and nature of any litigation concerning the controversy already begun by ... class members; (C) the desirability or undesirability of concentrating the litigation of the claims in the particular forum; and (D) the likely difficulties in managing a class action." Fed. R. Civ. P. 23(b)(3). "[W]hile these factors, structurally, apply to both predominance and superiority, they more clearly implicate the superiority inquiry." Sykes, 780 F.3d at 82 ; see also In re Am. Int'l Grp., Inc. Sec. Litig., 689 F.3d 229, 242 (2d Cir. 2012) ("[T]he plain text of Rule 23(b)(3) states that one of the 'matters pertinent' to a finding of predominance is 'the likely difficulties in managing a class action.' " (quoting Fed. R. Civ. P. 23(b)(3) )). "While Rule 23(b)(3) sets out four individual factors for courts to consider, manageability 'is, by the far, the most critical concern in determining whether a class action is a superior means of adjudication.' " Sykes, 780 F.3d at 82 (quoting 2 William B. Rubenstein, Newberg on Class Actions § 4:72 (5th ed. 2014) ). Despite the importance of manageability, the Second Circuit has also cautioned that "failure to certify an action under Rule 23(b)(3) on the sole ground that it would be unmanageable is disfavored and should be the exception rather than the rule." In re Petrobras, 862 F.3d at 268 (quoting In re Visa Check, 280 F.3d at 140 ). Ultimately, these factors are "nonexhaustive" and nonexclusive, Amchem, 521 U.S. at 615, 117 S.Ct. 2231, and "assessing superiority is a fact-specific inquiry," In re Vivendi, S.A., Sec. Litig., 838 F.3d 223, 264 (2d Cir. 2016). 1.4. Ascertainability In addition to the express requirements of Rule 23(a) and Rule 23 (b), the Second Circuit has "recognized an 'implied requirement of ascertainability' in Rule 23." Brecher v. Republic of Argentina, 806 F.3d 22, 24 (2d Cir. 2015) (quoting In re IPO, 471 F.3d at 30 ). Though "the touchstone of ascertainability is whether the class is 'sufficiently definite so that it is administratively feasible for the court to determine whether a particular individual is a member,' " id. (quoting 7A Charles A. Wright et al., Federal Practice & Procedure § 1760 (3d ed. 1998) ), the Second Circuit has clarified that ascertainability does not itself require that a proposed class be administratively feasible, see In re Petrobras, 862 F.3d at 268-69. Rather, ascertainability imposes only a "modest threshold requirement" that asks only "whether a proposed class is defined using objective criteria that establish a membership with definite boundaries." Id. at 269. It "will only preclude certification if a proposed class definition is indeterminate in some fundamental way." Id. Given that ascertainability is "distinct from the predominance requirement," id. at 264 n.15 (quoting In re IPO, 471 F.3d at 45 ), we do not read In re Petrobras to preclude a consideration of administrative feasibility concerns in analyzing predominance and superiority. Indeed, In re Petrobras reasoned that a freestanding administrative feasibility requirement as part of ascertainability would be duplicative of the manageability factor of the superiority inquiry (if administrative feasibility were considered comparatively rather than absolutely), id. at 268, and would "risk[ ] encroaching on territory belonging to the predominance requirement, such as classes that require highly individualized determinations of member eligibility," id. (citing Mazzei, 829 F.3d at 272 ). Accordingly, to the extent that any of the putative classes present administrative feasibility concerns, we will consider those issues not as part of the ascertainability analysis, but as part of the Rule 23(b)(3) predominance and superiority inquiries. 1.5. Modifications to the Class Definition As we have recognized in denying defendants' motions to strike plaintiffs' class-action allegations, "[a] court is not bound by the class definition proposed in the complaint and should not dismiss the action simply because the complaint seeks to define the class too broadly." May 13, 2016 Order, 2016 WL 2851333, at *2, slip op. at *3 (quoting Robidoux, 987 F.2d at 937 ), ECF No. 1408. Rule 23(c)(4) and Rule 23(c)(5) provide two specific means of modification, but a court also "has broad discretion to modify the class definition as appropriate." 5 Moore 's Federal Practice § 23.21[6] (3d ed. 2017). Rule 23(c)(4) provides that "[w]hen appropriate, an action may be brought or maintained as a class action with respect to particular issues." Fed. R. Civ. P. 23(c)(4). The rule may be applied "to certify a class on a particular issue even if the action as a whole does not satisfy Rule 23(b)(3)'s predominance requirement." In re Nassau Cty. Strip Search Cases, 461 F.3d 219, 225 (2d Cir. 2006). Additionally, "[i]f an action includes multiple claims, one or more of which might qualify as a certifiable class claim, the court may separate such claims from other claims in the action and certify them under the provisions of subsection (c)(4) of Rule 23." 1 McLaughlin on Class Actions § 4:44 (14th ed.) (Westlaw 2017) (internal quotation marks omitted); see also, e.g., In re AMF Bowling Sec. Litig., No. 99 Civ. 3023 (DC), 2002 WL 461513 (S.D.N.Y. Mar. 26, 2002). The Second Circuit has instructed that "[d]istrict courts should take full advantage of this provision to certify separate issues," Robinson v. Metro-N. Commuter R.R. Co., 267 F.3d 147, 167 (2d Cir. 2001) (alterations incorporated) (internal quotation marks omitted), abrogated on other grounds by Dukes, 564 U.S. 338, 131 S.Ct. 2541, but has also recognized that issue certification may be inappropriate if a "number of questions ... would remain for individual adjudication" or if issue certification "would not materially advance the litigation because it would not dispose of larger issues" relevant to the case. McLaughlin, 522 F.3d at 234. That is, "the rule should not be invoked merely to postpone confronting difficult certification questions," 7AA Charles A. Wright et al., Federal Practice & Procedure § 1790 (3d ed.) (Westlaw 2017), and indeed, overly aggressive application of Rule 23(c)(4) would nullify Rule 23(b)(3)'s predominance requirement, as a class may be certified only as to the common issues raised, cf. Castano v. Am. Tobacco Co., 84 F.3d 734, 745 n.21 (5th Cir. 1996) ("[T]he result would be automatic certification in every case where there is a common issue, a result that could not have been intended."). "[A] class action movant cannot gerrymander predominance by suggesting that only a single issue be certified for class treatment (in which, by definition, it will 'predominate')" when more substantial individual issues remain. 1 McLaughlin on Class Actions § 4:43 (14th ed.) (Westlaw 2017) (quoting Hyderi v. Wash. Mut. Bank, FA, 235 F.R.D. 390, 398 (N.D. Ill. 2006) ). Paralleling Rule 23(c)(4), Rule 23(c)(5) provides that "[w]hen appropriate, a class may be divided into subclasses that are each treated as a class under this rule." Fed. R. Civ. P. 23(c)(5). For example, when conflicts exist between class members, they "can be cured by dividing the class into separate 'homogeneous subclasses ... with separate representation to eliminate conflicting interests.' " In re Literary Works, 654 F.3d at 249-50 (quoting Ortiz v. Fibreboard Corp., 527 U.S. 815, 856, 119 S.Ct. 2295, 144 L.Ed.2d 715 (1999) ). However, the placement of plaintiffs into "multiple subclasses ... can generate unnecessary administrative inefficiencies," 3 William B. Rubenstein, Newberg on Class Actions § 7:30 (5th ed.) (Westlaw 2017) (footnote omitted), and "at some point there must be an end to reclassification," Ortiz, 527 U.S. at 857, 119 S.Ct. 2295 ; see also In re Literary Works, 654 F.3d at 257 (describing seven subclasses as "surely beyond the point at which 'reclassification with separate counsel' must end"). "The necessity of a large number of subclasses may indicate that common questions do not predominate," and "[t]he creation of a number of subclasses ... may make the case unmanageable [and] may defeat the superiority requirement." Manual for Complex Litigation § 21.23 (4th ed. 2004). Rule 23(c)(4) and Rule 23(c)(5) are phrased permissively. Consistent with the text of the rule, "[t]he court ... is not obligated to implement Rule 23(c)(4) [and Rule 23(c)(5) ] on its own initiative" by certifying classes only as to certain issues or creating subclasses. Lundquist v. Sec. Pac. Auto. Fin. Servs. Corp., 993 F.2d 11, 14 (2d Cir. 1993) (citing U.S. Parole Comm'n v. Geraghty, 445 U.S. 388, 408, 100 S.Ct. 1202, 63 L.Ed.2d 479 (1980) ); see also 7AA Charles A. Wright et al., Federal Practice & Procedure § 1790 (3d ed.) (Westlaw 2017) ("[T]he trial court has no independent obligation to utilize Rule 23(c)(4) sua sponte."). It remains "plaintiff's burden to show how the action may be [modified] to avoid certification problems." Lundquist, 993 F.2d at 14 (quoting Geraghty, 445 U.S. at 408, 100 S.Ct. 1202 ). Similarly, the decision to otherwise modify a class definition is a discretionary one. See Mazzei v. Money Store, 288 F.R.D. 45, 55 (S.D.N.Y. 2012) ("[C]ourts have the discretion to construe the complaint or redefine the class to bring it within the scope of Rule 23." (internal quotation marks omitted)); see also 7A Charles A. Wright et al., Federal Practice& Procedure § 1759 (3d ed.) (Westlaw 2017). Accordingly, in order to avoid "the perverse effect of turning defense counsel and the Court into plaintiffs' counsel's co-counsel, with plaintiffs waiting to see what objections defendants raise and how the Court rules on those objections and then amending their [proposed class definitions] as necessary based on what they learned in the process," LIBOR II, 962 F.Supp.2d at 626-27, we will consider issue certification under Rule 23(c)(4), subclass creation under Rule 23(c)(5), and other modifications of the proposed class definitions under our discretionary authority only where plaintiffs have set forth such proposals in sufficient detail. 2. Expert Opinion 2.1. The Daubert Standard Expert testimony is admissible under Rule 702 of the Federal Rules of Evidence, which provides in full: A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if: (a) the expert's scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue; (b) the testimony is based on sufficient facts or data; (c) the testimony is the product of reliable principles and methods; and (d) the expert has reliably applied the principles and methods to the facts of the case. Under the Supreme Court's decisions in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993), and Kumho Tire Co. v. Carmichael, 526 U.S. 137, 119 S.Ct. 1167, 143 L.Ed.2d 238 (1999), we have a " 'gatekeeping' function under Rule 702," under which we are "charged with 'the task of ensuring that an expert's testimony both rests on a reliable foundation and is relevant to the task at hand.' " Amorgianos v. Nat'l R.R. Passenger Corp., 303 F.3d 256, 265 (2d Cir. 2002) (quoting Daubert, 509 U.S. at 597, 113 S.Ct. 2786 ). "[T]he proponent of expert testimony has the burden of establishing by a preponderance of the evidence that the admissibility requirements of Rule 702 are satisfied." United States v. Williams, 506 F.3d 151, 160 (2d Cir. 2007). The Second Circuit has distilled Rule 702's requirements into three broad criteria: (1) qualifications, (2) reliability, and (3) relevance and assistance to the trier of fact. See Nimely v. City of New York, 414 F.3d 381, 396-97 (2d Cir. 2005). 2.1.1. Qualifications When presented with expert testimony, we first consider "the threshold question of whether a witness is 'qualified as an expert by knowledge, skill, experience, training, or education' to render his or her opinions." Id. at 396 n.11 (quoting Fed. R. Evid. 702 ). We analyze "the totality of the witness's background to determine whether he or she exhibits any one or more of the qualifications listed in Rule 702... with respect to a relevant field." Washington v. Kellwood Co., 105 F.Supp.3d 293, 304 (S.D.N.Y. 2015). As Rule 702's use of the disjunctive suggests, "any one of [the] five forms of qualifications will satisfy the rule." Tiffany (NJ) Inc. v. eBay, Inc., 576 F.Supp.2d 457, 458 (S.D.N.Y. 2007). "A formal education in a particular field is sufficient to qualify a witness as an expert" as a general matter, such that a "lack of extensive practical experience directly on point does not necessarily preclude [the] expert from testifying." Cary Oil Co. v. MG Ref. & Mktg., Inc., No. 99 Civ. 1725 (VM), 2003 WL 1878246, at *2 (S.D.N.Y. Apr. 11, 2003) (internal quotation marks omitted). Similarly, "a lack of formal training does not necessarily disqualify an expert from testifying if he or she has equivalent relevant practical experience." In re Rezulin Prods. Liab. Litig., 309 F.Supp.2d 531, 559 (S.D.N.Y. 2004). Indeed, "[c]ourts in this circuit have noted that an expert should not be required to satisfy an overly narrow test of his own qualifications." United States v. Tuzman, No. 15 Cr. 536 (PGG), 2017 WL 6527261, at *9 (S.D.N.Y. Dec. 18, 2017) (collecting cases) (quoting Arista Records LLC v. Lime Grp. LLC, No. 06 Civ. 5936 (KMW), 2011 WL 1674796, at *3 (S.D.N.Y. May 2, 2011) ). "[T]he Second Circuit [has] allowed an expert to testify as to matters within his general expertise even though he lacked qualifications as to certain technical matters within that field." Pension Comm. of the Univ. of Montreal Pension Plan v. Banc of Am. Sec., LLC, 691 F.Supp.2d 448, 457 (S.D.N.Y. 2010) (citing McCullock v. H.B. Fuller Co., 61 F.3d 1038, 1042-43 (2d Cir. 1995) ). We then "compare the area in which the witness has superior knowledge, education, experience, or skill with the subject matter of the proffered testimony," which must overlap. United States v. Tin Yat Chin, 371 F.3d 31, 40 (2d Cir. 2004). "[I]t is worth emphasizing that, because a witness qualifies as an expert with respect to certain matters or areas of knowledge, it by no means follows that he or she is qualified to express expert opinions as to other fields." Nimely, 414 F.3d at 399 n.13. Conversely, an expert's lack of qualifications as to some of the opinions offered does not render inadmissible the opinions that he is qualified to offer. 2.1.2. Reliability We next determine "whether the proffered testimony has a sufficiently 'reliable foundation' to permit it to be considered." Campbell ex rel. Campbell v. Metro. Prop. & Cas. Ins. Co., 239 F.3d 179, 184 (2d Cir. 2001) (quoting Daubert, 509 U.S. at 597, 113 S.Ct. 2786 ). "In this inquiry, [we] should consider the indicia of reliability identified in Rule 702, namely, (1) that the testimony is grounded on sufficient facts or data; (2) that the testimony 'is the product of reliable principles and methods'; and (3) that 'the witness has applied the principles and methods reliably to the facts of the case.' " Amorgianos, 303 F.3d at 265 (quoting Fed. R. Evid. 702). The Supreme Court has identified a number of factors that may be considered in assessing reliability: "(1) whether a theory or technique 'can be (and has been) tested,' (2) 'whether the theory or technique has been subjected to peer review and publication,' (3) a technique's 'known or potential rate of error,' and 'the existence and maintenance of standards controlling the technique's operation,' and (4) whether a particular technique or theory has gained 'general acceptance' in the relevant scientific community." Id. at 266 (citations omitted) (quoting Daubert, 509 U.S. at 593-94, 113 S.Ct. 2786 ). These factors are not a "definitive checklist or test," Daubert, 509 U.S. at 593, 113 S.Ct. 2786, as "the gatekeeping inquiry must be tied to the facts of a particular case," Kumho Tire, 526 U.S. at 150, 119 S.Ct. 1167 (internal quotation marks omitted), and "will necessarily vary from case to case," Amorgianos, 303 F.3d at 266. "[T]he law grants a district court the same broad latitude when it decides how to determine reliability as it enjoys in respect to its ultimate reliability determination." Restivo v. Hessemann, 846 F.3d 547, 576 (2d Cir. 2017) (emphasis omitted) (quoting Kumho Tire, 526 U.S. at 142, 119 S.Ct. 1167 ). Accordingly, "[i]n assessing the reliability of an expert opinion, a resort to common sense is not inappropriate." Johnson Elec. N. Am. Inc. v. Mabuchi Motor Am. Corp., 103 F.Supp.2d 268, 286 (S.D.N.Y. 2000). Though "flexible," the reliability inquiry "must focus on the principles and methodology employed by the expert, without regard to the conclusions the expert has reached or [our] belief as to the correctness of those conclusions." Amorgianos, 303 F.3d at 266. The expert's methodology is to be assessed step-by-step, and "it is critical that an expert's analysis be reliable at every step." Id. at 267. " [A]ny step that renders the analysis unreliable under the Daubert factors renders the expert's testimony inadmissible." Id. (emphasis omitted) (quoting In re Paoli R.R. Yard PCB Litig., 35 F.3d 717, 745 (3d Cir. 1994) ). "But conclusions and methodology are not entirely distinct from one another." Gen. Elec. Co. v. Joiner, 522 U.S. 136, 146, 118 S.Ct. 512, 139 L.Ed.2d 508 (1997). "[N]othing in either Daubert or the Federal Rules of Evidence requires a district court to admit opinion evidence that is connected to existing data only by the ipse dixit of the expert," and "[a] court may conclude that there is simply too great an analytical gap between the data and the opinion proffered." Id. That is, "when an expert opinion is based on data, a methodology, or studies that are simply inadequate to support the conclusions reached, Daubert and Rule 702 mandate the exclusion of that unreliable opinion testimony." Amorgianos, 303 F.3d at 266. We offer three additional observations regarding the incomplete distinction between "methodology" on the one hand and "conclusions" and "results" on the other. First, a challenge to an expert's methodology will necessarily call into question the conclusions derived from the application of that methodology. Such a challenge does not impermissibly attack an expert's results simply because those results are collaterally damaged by the challenge directed towards the expert's methodology. Second, robustness testing of an expert's methodology-by applying that methodology to different data or with different assumptions and examining the results produced by the methodology so applied-is not an impermissible challenge to the expert's results. Rather, this robustness and sensitivity testing relates directly to two of the Daubert factors articulated by the Supreme Court: whether the methodology "can be (and has been) tested" and the methodology's "known or potential rate of error." Daubert, 509 U.S. at 594, 113 S.Ct. 2786. Robustness testing and sensitivity testing that produces contradictory or otherwise implausible results strongly suggest that a methodology has been insufficiently tested and that the methodology has a high potential rate of error. Third, inconsistent results are an "indicia of unreliability" in an expert's methodologies. Lippe v. Bairnco Corp., 99 Fed.Appx. 274, 279 (2d Cir. 2004). This principle is clearest in the context of inconsistent results produced by the same methodology. See, e.g., Louis Vuitton Malletier v. Dooney & Bourke, Inc., 525 F.Supp.2d 558, 569 (S.D.N.Y. 2007) (finding "unexplained inconsistency between the results" produced by two iterations of the same methodology to be a basis for exclusion); United States v. Hermanek, 289 F.3d 1076, 1097 (9th Cir. 2002) ("Inconsistent results may be an indicator of unreliability."). However, it is no less applicable to multiple methodologies intended to measure the same phenomenon that ultimately produce inexplicably inconsistent results. See Lippe, 99 Fed.Appx. at 279 ; see also In re Paoli, 35 F.3d at 777 (identifying "inconsistent results" produced by two analyses as supporting the exclusion of an expert's evidence). "When faced with expert testimony that contains both reliable and unreliable opinions, district courts often exclude only the unreliable testimony." In re Pfizer Inc. Sec. Litig., 819 F.3d 642, 665 (2d Cir. 2016). If "the unreliable portion of an opinion can easily be distinguished from testimony that could help the [trier of fact], it may be an abuse of discretion to throw the good out with the bad." Id. However, "[we] are 'not obligated to prune away all of the problematic' elements of an expert's proposed testimony 'to save the remaining portions, however small.' " Id. (quoting Bricklayers & Trowel Trades Int'l Pension Fund v. Credit Suisse Sec. (USA) LLC, 752 F.3d 82, 96 (1st Cir. 2014) ). 2.1.3. Relevance and Assistance to the Factfinder "Even after determining that a witness is 'qualified as an expert' to testify as to a particular matter, and that the opinion is based upon reliable data and methodology, Rule 702 [ (a) ] requires the district court to make a third inquiry: whether the expert's testimony ... will 'assist the trier of fact' " in understanding the evidence or determining a fact in issue. Nimely, 414 F.3d at 397 (citations omitted) (quoting Fed. R. Evid 702 ). "This condition goes primarily to relevance," Daubert, 509 U.S. at 591, 113 S.Ct. 2786, as "[e]xpert testimony which does not relate to any issue in the case is not relevant and, ergo, non-helpful," Raskin v. Wyatt Co., 125 F.3d 55, 66 (2d Cir. 1997) (alteration in original) (quoting Daubert, 509 U.S. at 591, 113 S.Ct. 2786 ). Relevance, in turn, is assessed with respect to Rule 401 of the Federal Rules of Evidence : "whether it 'ha[s] any tendency to make the existence of any fact that is of consequence to the determination of the action more probable or less probable than it would be without the evidence.' " Campbell, 239 F.3d at 184 (alteration in original) (quoting Fed. R. Evid. 401 ). Accordingly, the Second Circuit has "consistently held ... that expert testimony that usurps either the role of the trial judge" in determining "the applicable law or the role of the [trier of fact] in applying that law to the facts before it" is inadmissible because it "by definition does not aid the [trier of fact] in making a decision," Nimely, 414 F.3d at 397 (quoting United States v. Bilzerian, 926 F.2d 1285, 1294 (2d Cir. 1991) and United States v. Duncan, 42 F.3d 97, 101 (2d Cir. 1994) ) (alterations incorporated and citations omitted). Similarly, "expert testimony that seeks to address 'lay matters which [the trier of fact] is capable of understanding and deciding without the expert's help' is not relevant and is therefore inadmissible." United States v. Jiau, 734 F.3d 147, 154 (2d Cir. 2013) (quoting Andrews v. Metro N. Commuter R.R. Co., 882 F.2d 705, 708 (2d Cir. 1989) ). That is, testimony addressing lay matters is not based on an "expert's scientific, technical, or other specialized knowledge," and therefore fails to satisfy the first part of Rule 702(a). Accordingly, it is "inappropriate for experts to become a vehicle for factual narrative." SEC v. Tourre, 950 F.Supp.2d 666, 675 (S.D.N.Y. 2013) (citing, inter alia, Highland Capital Mgmt., L.P. v. Schneider, 551 F.Supp.2d 173, 187 (S.D.N.Y. 2008) ). As with qualifications and reliability, we also disaggregate an expert's opinions before assessing their relevance and helpfulness: the fact that some of an expert's opinions are irrelevant does not render all of the expert's opinions inadmissible. Nonetheless, we need not overly fragment an expert's opinions in order to pick out only the relevant and helpful portions. Cf. In re Pfizer, 819 F.3d at 665. 2.2. Application at Class Certification "Neither the Supreme Court nor the Second Circuit has definitely decided whether the Daubert standard governs the admissibility of expert evidence submitted at the class certification stage." Adkins v. Morgan Stanley, 307 F.R.D. 119, 148 (S.D.N.Y. 2015) (quoting Chen-Oster v. Goldman, Sachs & Co., 114 F.Supp.3d 110, 114 (S.D.N.Y. 2015) ). Indeed, the issue remains unsettled nationally and in this district. Compare, e.g., In re Blood Reagents Antitrust Litig., 783 F.3d 183, 187 (3d Cir. 2015) ("[A] plaintiff cannot rely on challenged expert testimony, when critical to class certification, to demonstrate conformity with Rule 23 unless the plaintiff also demonstrates, and the trial court finds, that the expert testimony satisfies the standard set out in Daubert."); Messner v. Northshore Univ. HealthSystem, 669 F.3d 802, 812-14 (7th Cir. 2012) ; Ellis v. Costco Wholesale Corp., 657 F.3d 970, 982 (9th Cir. 2011) ; Sher v. Raytheon Co., 419 Fed.Appx. 887, 890-91 (11th Cir. 2011) ; and Ge Dandong v. Pinnacle Performance Ltd., No. 10 Civ. 8086 (JMF), 2013 WL 5658790, at *13 (S.D.N.Y. Oct. 17, 2013), with, e.g., In re Zurn Pex Plumbing Prods. Liab. Litig., 644 F.3d 604, 613 (8th Cir. 2011) ("The main purpose of Daubert exclusion is to protect juries from being swayed by dubious scientific testimony. That interest is not implicated at the class certification stage where the judge is the decision maker."), and In re Scotts EZ Seed Litig., 304 F.R.D. 397, 412 n.8 (S.D.N.Y. 2015) (analyzing "whether each of [the expert's] proposed methodologies satisfy Comcast" rather than conducting a Daubert analysis). We are persuaded by the view that expert evidence submitted at the class certification stage is subject to the Daubert standard. First, the Supreme Court has suggested in dicta that Daubert applies, commenting that "the District Court concluded that Daubert did not apply to expert testimony at the certification stage of class-action proceedings. We doubt that is so...." Dukes, 564 U.S. at 354, 131 S.Ct. 2541. Not only has the Second Circuit characterized this statement as "suggesting that a Daubert analysis may be required at least in some circumstances," In re U.S. Foodservice Inc. Pricing Litig., 729 F.3d 108, 129 (2d Cir. 2013), but this statement (though dicta) is also "the only discussion of [the issue] by the Supreme Court of which we are aware" such that we consider it "to be persuasive authority here," Tiffany (NJ) Inc. v. eBay Inc., 600 F.3d 93, 108 (2d Cir. 2010). Second, we interpret the Second Circuit's decisions in In re IPO, Bombardier, and In re U.S. Foodservice, as supporting a more searching examination of expert testimony offered at the class certification stage. See 1 McLaughlin on Class Actions § 3:14 (14th ed.) (Westlaw 2017) (describing the Second Circuit's "substantial expansion of the extent to which district courts may evaluate expert testimony on class certification" and citing, inter alia, In re IPO and Bombardier ). Though the Second Circuit did not decide in In re U.S. Foodservice whether or when a Daubert analysis forms a necessary component of a district court's rigorous analysis," it reasoned that "[i]n In re IPO, we disavowed our earlier statement that 'an expert's testimony may establish a component of a Rule 23 requirement simply by not being fatally flawed.' " In re U.S. Foodservice, 729 F.3d at 129-30 (quoting In re IPO, 471 F.3d at 41 ). Indeed, given the Second Circuit's direction that we consider "the relevant evidence admitted at the class certification stage," In re IPO, 471 F.3d at 42 (emphasis added), it appears to us that the standard rules of evidence should apply, see Chen-Oster, 114 F.Supp.3d at 114 (" Daubert is an amplification of Rule 702, and the Federal Rules of Evidence apply generally to 'proceedings' in the courts of the United States."). Third, at least two leading treatises endorse this view. "An undiluted Daubert analysis is consonant with a class certification standard that requires a determination by a preponderance of the evidence that each Rule 23 requirement has been met, and under which head-to-head weighing of competing expert evidence is proper." 1 McLaughlin on Class Actions § 3:14 (14th ed.) (Westlaw 2017). "It is not sufficient for the court simply to determine that the testimony could evolve into something admissible by the time of trial." 7AA Charles A. Wright et al., Federal Practice & Procedure § 1785 (4th ed.) (Westlaw 2017). Though we conclude that Daubert applies, our inquiry is guided by the purpose for which the evidence is introduced-establishing the various class certification requirements. "[T]he question is not whether a jury at trial should be permitted to rely on the expert's report to find facts as to liability, but rather whether the Court may utilize it in deciding whether the requisites of Rule 23 have been met." Pinnacle Performance, 2013 WL 5658790, at *13 (alterations incorporated) (quoting In re Visa Check/MasterMoney Antitrust Litig., 192 F.R.D. 68, 77 (E.D.N.Y. 2000) ); see also Fort Worth Emps.' Ret. Fund v. J.P. Morgan Chase & Co., 301 F.R.D. 116, 126 (S.D.N.Y. 2014) (limiting the Daubert inquiry "to whether or not the expert reports are admissible to establish the requirements of Rule 23" (quoting Pinnacle Performance, 2013 WL 5658790, at *13 )). However, "[a] conclusion that proffered expert evidence is sufficiently reliable and relevant to pass Daubert muster does not end the inquiry on class certification." 1 McLaughlin on Class Actions § 3:14 (14th ed.) (Westlaw 2017); see In re IPO, 471 F.3d at 42 ("[W]e also disavow the suggestion ... that an expert's testimony may establish a component of a Rule 23 requirement simply by being not fatally flawed."). Rather, expert opinion deemed to be admissible comprises only one part of "the relevant evidence admitted at the class certification stage" to be weighed in determining "whether each Rule 23 requirement has been met," In re IPO, 471 F.3d at 42, and each requirement must still be established by a preponderance of the evidence, see Bombardier, 546 F.3d at 202. Therefore, to the extent that flaws in expert testimony proffered at class certification do not warrant that testimony's exclusion by the Court as gatekeeper under Daubert at the threshold, those flaws may nonetheless be considered in the Rule 23 analysis undertaken by the Court as trier of fact. Put differently, though a Daubert motion is an improper venue in which to take sides in a "battle of the experts" offered by competing parties, In re Joint E. & S. Dist. Asbestos Litig., 52 F.3d 1124, 1135 (2d Cir. 1995), disputes between experts must be resolved if necessary to the Rule 23 analysis, see In re IPO, 471 F.3d at 42. III. EXCHANGE-BASED ACTION Exchange plaintiffs seek certification of a class comprised of traders of Eurodollar futures (EDF) contracts and options on EDF contracts. Specifically, they seek certification of a class defined as follows: All persons, corporations and other legal entities (other than Defendants, their employees, affiliates, parents, subsidiaries, and co-conspirators) ("Eligible Persons") that transacted in Eurodollar futures and options on Eurodollar futures on the Chicago Mercantile Exchange between January 1, 2005 and May 17, 2010 (the "Class Period") and that were harmed or satisfy one or more of "A," "B," or "C" below. The proposed class definition then defines three subcriteria, the second of which consists of three sub-subcriteria and the third of which consists of two sub-subcriteria: SUBPART A. Eligible Persons that sold a Eurodollar futures contract, or bought a put option or sold a call option on Eurodollar futures before August 7, 2007 and purchased all or part of this short position back at the final expiration formula price of a Eurodollar futures contract expiring after August 7, 2007 and before May 17, 2010. SUBPART B. Eligible Persons that (1) purchased Eurodollar futures contract(s) or call options on Eurodollar futures on the following dates: April 7, 2006, August 17, 2006, October 26, 2006, and December 22, 2006; or (2) sold Eurodollar futures contracts or purchased put options on Eurodollar futures on the following dates: September 29, 2005, November 28, 2005, June 30, 2006, September 1, 2006, November 29, 2006, February 28, 2007, March 1, 2007, July 30, 2007, and August 6, 2007; or (3) purchased or sold Eurodollar futures contracts (or options) and that were harmed between January 1, 2005 and August 6, 2007 inclusive. SUBPART C. Eligible Persons that initiated a Eurodollar futures contract or options position on or after April 15, 2009 and on or before May 17, 2010 ("Period 3"), and who satisfy "1" or "2" below. 1. Eligible Persons included in "C" are those that purchased or sold a Eurodollar futures or options contract to initiate a position during Period 3 and that were harmed. 2. Eligible Persons included in "C" are also those that purchased a Eurodollar futures contract (including Eurodollar futures contracts the expiration for which was less than 365 calendar days after the date of such purchase) to initiate a long position during Period 3, and continued to hold all or part of such long position until liquidating the position after Period 3. The operative Corrected Fourth Amended Consolidated Class Action Complaint, identified panel banks Bank of America, Barclays, Citi, Deutsche Bank, JPMorgan Chase, Rabobank, and UBS (and certain affiliates of these panel banks) as defendants. (Corrected Fourth Am. Consolidated Class Action Compl. ("Corrected 4AC") ¶¶ 34-38, 45, 57-59, 66-68, 77-78, Dec. 11, 2017, ECF No. 2363.) Exchange plaintiffs assert five claims, four under the Commodities Exchange Act (CEA) and the fifth under the Sherman Act. The CEA claims are asserted against all defendants, whereas the antitrust claims are asserted against only Bank of America, Citi, and JPMorgan Chase consistent with our rulings in LIBOR VI, see 2016 WL 7378980, at *25, slip op. at app. A-1. (Corrected 4AC ¶¶ 668-705.) The scope of claims remaining in this action has also been narrowed by several settlements between Exchange plaintiffs and particular defendants. We preliminarily approved a settlement with Barclays, see Dec. 2, 2014 Order, 2014 WL 6851096, ECF No. 861, and we deferred preliminary approval of the settlements with Citi and Deutsche Bank (Letter from Christopher Lovell & David Kovel to the Court, Oct. 11, 2017, ECF No. 2307) pending our resolution of the class-certification motions. Bank of America and JPMorgan Chase have also reached settlements with Exchange plaintiffs, though no documentation memorializing the settlement has yet been filed. (Jan. 18, 2018 Hr'g Tr. ("Hr'g Tr.") 24:10-25:21.) As a result of these settlements, only CEA claims remain in this action: those based on trader-based manipulation under direct and vicarious liability theories against Rabobank, and those based on persistent suppression under direct, vicarious liability, and aiding and abetting theories against UBS. (Corrected 4AC ¶¶ 668-705.) As part of briefing the motion for class certification, the parties have submitted reports and deposition testimony from eight experts. Seven of these experts' opinions have prompted Daubert motions. Rabobank has moved to exclude the opinions of (1) Dr. H. Nejat Seyhun, (2) Dr. Janet Netz, (3) Mr. Craig Beevers, and (4) Mr. Eric Miller. Exchange plaintiffs have moved to exclude the opinions of (5) Dr. Robert Willig, (6) Dr. Christopher Culp, and (7) Dr. R. Glenn Hubbard. We first consider the Daubert motions before proceeding to the motion for class certification itself. 1. Rabobank's Daubert Motions 1.1. Dr. Seyhun Exchange plaintiffs offer two reports from Dr. H. Nejat Seyhun: (1) an initial report dated February 2, 2017 (Decl. of David Kovel ex. G., July 10, 2017, ECF No. 2071); and (2) a rebuttal report dated May 3, 2017 (Decl. of Jefferson Bell ex. 5, June 30, 2017, ECF No. 2008). We refer to these as the Seyhun Initial Report and the Seyhun Rebuttal Report. Across these two reports, Dr. Seyhun's opinions relate primarily to two subjects: (1) the determination of what LIBOR, and each bank's LIBOR submissions, would have been but-for the alleged manipulative conduct, and (2) the determination of what effect changes in LIBOR have on the trading prices of EDF contracts and options. Rabobank does not challenge Dr. Seyhun's qualifications, and we agree that Dr. Seyhun is well qualified to offer these opinions. 1.1.1. Models of But-For Published LIBOR and But-For LIBOR Submissions Dr. Seyhun first opines that certain statistical and mathematical analyses can demonstrate that the defendants' alleged conduct impacted LIBOR and calculate the amount of impact. (Seyhun Initial Report ¶ 12.) To support this conclusion, Dr. Seyhun offers several models for estimating but-for LIBOR and each bank's but-for LIBOR submissions as evidence that these statistical and mathematical analyses are available. (E.g., Seyhun Initial Report ¶ 87.) In his initial report, Dr. Seyhun offers two methodologies that involve first the calculation of but-for published LIBOR and then the derivation of each bank's but-for LIBOR submission from but-for published LIBOR. In his rebuttal report, Dr. Seyhun offers two additional models that are entirely distinct from the two models presented in his initial report. In each of these models, Dr. Seyhun first calculates but-for LIBOR submissions for each panel bank and then applies the BBA's trimming methodology-which excludes the top quartile of submissions and the bottom quartile of submissions and averages the remaining submissions-in order to determine but-for published LIBOR. The two models presented in Dr. Seyhun's initial report each begin with the calculation of but-for published LIBOR. Dr. Seyhun models the mathematical relationship between LIBOR and a reference rate on a daily basis during a "clean period" using an ordinary least squares (OLS) regression, and uses that relationship to predict LIBOR over the Class Period. Though Dr. Seyhun varies the reference rate and clean period at various points in his report, Dr. Seyhun primarily uses the ICAP-Ask rate as the reference rate and the aggregated period from 2000 through 2004 combined with 2013 as the clean period. (Seyhun Initial Report ¶¶ 70-78, tbl.2.2.) Dr. Seyhun defines LIBOR "artificiality" to be the difference between his calculated but-for published LIBOR and actual published LIBOR and tests the statistical significance of the artificiality during the Suppression Period (but not Period 0) using another regression. (Seyhun Initial Report tbl.2.3.) Dr. Seyhun also estimates but-for LIBOR using the ICAP-Ask rate as the reference rate in a second regression. Otherwise identical, this second ICAP-Ask model uses a clean period of 2000 through 2002 aggregated with 2013. Dr. Seyhun presents an analysis of the statistical significance of his artificiality estimates based on this specification (Seyhun Initial Report tbl.2.4), but does not present the results of the regression itself and does not reference this 2000-2002 plus 2013 regression elsewhere in his initial report. Dr. Seyhun then derives, for each panel bank, but-for LIBOR submissions from the first ICAP-Ask-based model of but-for LIBOR using two different methods. Under the first method (the "Relative Artificiality" model), Dr. Seyhun assesses the "relative artificiality" of a bank's submission by calculating the difference between a bank's actual submission and actual published LIBOR. If the bank's submission was not trimmed from the calculation of published LIBOR, the relative artificiality equals the difference between published LIBOR and the bank's LI