Securities expert witnesses

Expert class library · 5 classes

The experts in securities class actions and Securities Act cases: event studies, market efficiency, loss causation and damages, and the economists the defense calls to answer them.

Each class is defined by role and method, never by a person or a firm. Open one for what it is retained to answer, how its testimony is attacked under Rule 702, and the rulings, each read in the opinion.

Usually retained by plaintiffs

Plaintiff event-study and loss-causation econometrician

Single-firm event study · Disaggregation of confounding information

Market-efficiency expert

Cammer factor analysis · Krogman factor analysis

Usually retained by the defense

Defense event-study econometrician

Market-model event study · Price impact rebuttal

Section 11 negative causation economist

Event study of disclosure dates · Market and industry index comparison

Retained by either side

Securities accounting and GAAP expert

GAAP compliance review · Restatement analysis

Recent rulings

The 12 most recent of 22 rulings in this practice, newest first. Each links to the free opinion on CourtListener and to the class it belongs to.

OutcomeCaseCourtExpert class
Exclusion reversedOhio Public Employees Retirement System v. Federal Home Loan Mortgage Corp.No. 25-3765 (6th Cir. Aug. 21, 2026)6th Cir. 2026Market-efficiency expert
Sent back for reviewGA Firefighters' Pension v. Anadarko Petroleum Corp.99 F.4th 7705th Cir. 2024Plaintiff event-study and loss-causation econometrician
AdmittedArk. Tchr. Ret. Sys. v. Goldman Sachs Grp., Inc.77 F.4th 742d Cir. 2023Defense event-study econometrician
LimitedIn re Fannie Mae/Freddie Mac Senior Preferred Stock Purchase Agreement Class Action LitigationsMisc. No. 2013-1288 (D.D.C. Oct. 21, 2022)D.D.C. 2022Defense event-study econometrician
AdmittedCity of Cape Coral Mun. Firefighters' Ret. Plan v. Emergent Biosolutions, Inc.322 F. Supp. 3d 676D. Md. 2018Market-efficiency expert
AdmittedWillis v. Big Lots, Inc.242 F. Supp. 3d 634S.D. Ohio 2017Market-efficiency expert
AdmittedIn re Vivendi, S.A. Securities Litigation838 F.3d 2232d Cir. 2016Plaintiff event-study and loss-causation econometrician
Exclusion reversedTeachers' Retirement System v. Pfizer, Inc.819 F.3d 6422d Cir. 2016Plaintiff event-study and loss-causation econometrician
AdmittedCarpenters Pension Trust Fund v. Barclays PLC310 F.R.D. 69S.D.N.Y. 2015Plaintiff event-study and loss-causation econometrician
AdmittedErica P. John Fund, Inc. v. Halliburton Co.309 F.R.D. 251N.D. Tex. 2015Defense event-study econometrician
ExcludedFederal Housing Finance Agency v. Nomura Holding America, Inc.104 F. Supp. 3d 441S.D.N.Y. 2015Section 11 negative causation economist
ExcludedBricklayers & Trowel Trades International Pension Fund v. Credit Suisse Securities (USA) LLC752 F.3d 821st Cir. 2014Plaintiff event-study and loss-causation econometrician

Other practice areas

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The library summarises public decisions for orientation; it is not legal advice. Read the opinion before relying on any ruling. No individual expert is named.