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Karen M. Lerner
Partner
- New York
-
250 Park Avenue
Suite 820
New York, NY 10177 - 212.371.6600
Biography
Biography
Karen M. Lerner is a partner in our New York office focused on antitrust and commodities litigation.
Over the course of her career, Ms. Lerner has successfully litigated complex class actions that have recovered billions of dollars on behalf of institutional and individual plaintiffs. She has played important roles in several landmark antitrust cases and remains one of the few women ever appointed as Interim Co-Lead Class Counsel in a Commodity Exchange Act case. In addition to her litigation work, she also advises individuals, corporations, and nonprofits regarding business practices and corporate governance. In 2022, Ms. Lerner was named a Fellow of the American Bar Foundation, a global honorary society limited to one percent of lawyers licensed to practice in each jurisdiction.
Prior to joining KM, Ms. Lerner was of counsel at McDonough, Korn & Eichhorn, where she handled cases up to and including at trial.
Ms. Lerner is actively involved in promoting volunteerism in the legal community and through women’s organizations. She is an advocate for diversity and inclusion and is a member of Women Antitrust Plaintiffs’ Attorneys (WAPA), an organization for female attorneys who focus their legal practice on representing businesses injured by cartels or other anticompetitive activities. Finally, in addition to her legal practice and activities, Ms. Lerner has served as a member of the Board of Directors for several charitable organizations.
Prior to joining KM, Ms. Lerner was of counsel at McDonough, Korn & Eichhorn, where she handled cases up to and including at trial.
Ms. Lerner is actively involved in promoting volunteerism in the legal community and through women’s organizations. She is an advocate for diversity and inclusion and is a member of Women Antitrust Plaintiffs’ Attorneys (WAPA), an organization for female attorneys who focus their legal practice on representing businesses injured by cartels or other anticompetitive activities. Finally, in addition to her legal practice and activities, Ms. Lerner has served as a member of the Board of Directors for several charitable organizations.
- The University at Albany, SUNY (B.A. summa cum laude, Phi Beta Kappa, 1988)
- University of Pennsylvania School of Law (J.D. 1991)
- The United States Supreme Court
- United States Courts of Appeals for the Second and Third Circuits
- United States Court of Appeals for the District of Columbia
- United States District Courts for the Southern and Eastern Districts of New York
- United States District Court for the District of New Jersey
- New York State Bar
- New Jersey State Bar
- The District of Columbia Bar
National Law Journal Elite Women of the Plaintiffs Bar, 2022-2023
Top Rated Antitrust Litigation Attorney, Super Lawyers, 2021-2024
Top Women Attorneys in New York, Super Lawyers 2023-2024
New York Metro Super Lawyers, 2025
Honoree, Inaugural 40 Over 40 Award, Association of the Junior Leagues International (AJLI), 2025
Top Attorneys in the New York Metro Area, American Registry, 2021, 2024
Top Women Attorneys in the New York Metro Area, American Registry, 2022, 2025
Law360's Competition Editorial Advisory Board, 2022-2023
Top Rated Antitrust Litigation Attorney, Super Lawyers, 2021-2024
Top Women Attorneys in New York, Super Lawyers 2023-2024
New York Metro Super Lawyers, 2025
Honoree, Inaugural 40 Over 40 Award, Association of the Junior Leagues International (AJLI), 2025
Top Attorneys in the New York Metro Area, American Registry, 2021, 2024
Top Women Attorneys in the New York Metro Area, American Registry, 2022, 2025
Law360's Competition Editorial Advisory Board, 2022-2023
Experience
Some of Ms. Lerner's antitrust and commodities experience includes:
- Co-lead counsel in In re Credit Default Swaps Auctions Litigation, a class action brought by the firm and the Office of the Attorney General for the State of New Mexico alleging antitrust violations and market manipulation in the credit default swaps market. The case is ongoing.
- Court-appointed executive committee member and class counsel in In re Digital Advertising Antitrust Litigation, representing publishers alleging that Google monopolized and suppressed competition in online display advertising.
- Representation of the exchange-based class in In re LIBOR-Based Financial Instruments Antitrust Litigation, an antitrust case alleging that defendant banks colluded to misreport and manipulate LIBOR. The case resulted in settlements totaling $190.45 million, which combined represent the largest recovery in a “futures-only” commodities class action litigation.
- Special fiduciary representation for the exchange-based class in In re Foreign Exchange Benchmark Rates Antitrust Litigation for a putative class of participants who traded futures and options in the FX market. The case has already resulted in partial settlements of more than $2.3 billion.
- Counsel in the benchmark antitrust litigation In re Commodity Exchange, Inc., Gold Futures and Options Trading Litigation, on behalf of a putative class of gold derivative traders. The case has resulted in settlements of $152 million.
- Selected by the Court as co-lead counsel in In re J.P. Morgan Treasury Futures Spoofing Litigation, alleging that defendants manipulated U.S. Treasury futures for more than a decade and that this conduct contributed to the bank’s recent $920 million settlement with the DOJ, CFTC, and SEC. The case has a putative settlement of $15.7 million.
- Court-appointed executive committee member and class counsel in In re Cattle Antitrust Litigation, representing cattle producers and cattle futures traders. The suit alleges that the “Big 4” meatpacking firms conspired to suppress prices for fed cattle and manipulated live cattle futures traded on the Chicago Mercantile Exchange.
- Representation of exchange-based investors in Shak v. J.P. Morgan Chase & Co., alleging monopolization and manipulation of the silver futures market in violation of federal antitrust and commodity exchange laws. The parties successfully reached a private settlement. The case preceded a related Department of Justice criminal investigation into J.P. Morgan that remains ongoing.
- Counsel in In re Deutsche Bank Spoofing Litigation on behalf of a putative class of investors alleging manipulation through “spoofing” of U.S. Treasury futures traded on the Chicago Board of Trade and Eurodollar futures traded on the Chicago Mercantile Exchange.
- Court-appointed to the executive committee and class counsel in In re Bank of Nova Scotia Spoofing Litigation, alleging that defendants manipulated precious metals futures traded on the New York Mercantile Exchange and the Commodity Exchange, Inc.
- Representation of a putative class of exchange-based investors in Dennis v. The Andersons, Inc. et al., alleging monopolization and manipulation of Chicago Board of Trade soft red winter wheat futures contracts in violation of federal antitrust and commodity exchange laws.
- Court-appointed discovery committee co-chair in In re Effexor XR Antitrust Litigation for a putative class of direct purchasers of brand name and generic equivalents of extended-release venlafaxine hydrochloride capsules against drug manufacturers. Among the claims, Defendants are alleged to have delayed market entry of generic versions and entered into reverse payment settlements.
- Representation as sole lead counsel in In re North Sea Brent Crude Oil Futures Litigation.
- Representation of a whistleblower in Anonymous, et ano. v. Moody's Corporation, et al., No. 103997/2012 (Sup. Ct. N.Y. Cty. and First Dept.), alleging millions of dollars of tax fraud using a sham captive insurance company for over a decade regarding domestic and international transactions. The litigation settled for $8.5 million.
- Maverick v. Valeant Pharmaceuticals International, Inc., alleging that Valeant materially misrepresented its business model, touting artificial and unsustainable growth that was enabled by the company’s deceptive and illegal conduct.
Cases & Investigations
- Case / Company Name
- Type
- Status
-
Name
Maverick Neutral Levered Fund, Ltd. v. Valeant Pharmaceuticals International, Inc.,
No. 20-cv-02190 (D.N.J.). - Type Securities
- Status Pending
-
We are acting as counsel in this securities class action alleging that Valeant materially misrepresented its business model, touting artificial and unsustainable growth that was enabled by the company’s deceptive and illegal conduct. The case has important implications not only for Valeant’s shareholders, who sustained significant losses when the company’s misrepresentations were disclosed, but for corporate governance in the pharmaceutical industry as a whole, and for consumers: Valeant’s growth during the class period was driven not by “organic growth” sustained by volume increases and cost savings, but by price gouging (ex: within two days of acquiring the rights to Nitropress and Isuprel, two drugs used to treat emergency heart conditions, Valeant increased their prices by 212% and 525%, respectively).
-
Name
In re Credit Default Swaps Auctions Litigation,
No. 21-cv-00606 (D.N.M.). - Type Antitrust, Commodities
- Status Pending
-
We are acting as lead counsel on behalf of the New Mexico Attorney General’s Office and the New Mexico State Investment Council alleging that leading credit default swap (CDS) dealers took part in a more than decade-long, multibillion-dollar scheme to manipulate the benchmark prices used to value credit default swap contracts at settlement.
- Name In re Digital Advertising Antitrust Litigation, No. 20-cv-03556 (N.D. Cal.).
- Type Antitrust
- Status Pending
-
Acting as a court-appointed executive committee member and class counsel representing publishers alleging that Google monopolized and suppressed competition in online display advertising.
-
Name
In re Effexor XR Antitrust Litigation,
No. 11-cv-5479 (D.N.J.). - Type Antitrust, Healthcare Fraud
- Status Pending
-
Acting as lead counsel and head of the discovery committee to a putative class of direct purchasers of brand name and generic equivalents of extended-release venlafaxine hydrochloride capsules against drug manufacturers. Among the claims, defendants are alleged to have delayed market entry of generic versions and entered reverse payment settlements.
-
Name
In re North Sea Brent Crude Oil Futures Litigation,
No. 13-md-02475 (S.D.N.Y.). - Type Antitrust, Commodities
- Status Pending
-
Sole lead counsel on behalf of a proposed class of Brent crude oil futures traders alleging benchmark manipulation.
-
Name
CFTC v. Shak,
No. 14-cv-01632 (D.D.C.). - Type Commodities
- Status Pending
-
Representation of a defendant in a case brought by the CFTC under the Commodity Exchange Act’s newest provisions for violations of an administrative order in the gold futures market.
-
Name
In re Bank of Nova Scotia Spoofing Litigation,
No. 20-cv-11059 (D.N.J.). - Type Commodities
- Status Settled
-
As a court-appointed executive committee member, the firm has served in a leadership capacity in this case which alleges that defendants manipulated precious metals futures traded on the New York Mercantile Exchange and the Commodity Exchange, Inc. This matter is important in that it seeks to curb manipulative and abusive practices by dominant financial institutions and make metals futures markets more efficient.
-
Name
In re Cattle Antitrust Litigation,
No. 19-cv-1222 (D. Minn.). - Type Commodities
- Status Pending
-
Court-appointed executive committee member and class counsel representing cattle producers and cattle futures traders in a lawsuit alleging that the “Big 4” meatpacking firms conspired to suppress prices for fed cattle and manipulated live cattle futures traded on the Chicago Mercantile Exchange.
-
Name
In re Commodity Exchange, Inc., Gold Futures and Options Trading Litigation,
No. 14-md-02548 (S.D.N.Y.). - Type Commodities
- Status Pending
-
Counsel for plaintiff on behalf of gold purchasers in a market manipulation case. The case has already resulted in partial settlements of $60 million.
-
Name
In re Deutsche Bank Spoofing Litigation,
No. 20-cv-03638 (N.D. Ill.). - Type Commodities
- Status Pending
-
Co-lead counsel on behalf of a putative class of investors in this trading markets manipulation case alleging manipulation through “spoofing” of U.S. Treasury futures traded on the Chicago Board of Trade and Eurodollar futures traded on the Chicago Mercantile Exchange. This matter is important because it seeks to curb manipulative and abusive practices by dominant financial institutions and make Treasury futures markets more efficient.
-
Name
Dennis v. The Andersons, Inc.,
No. 20-cv-04090 (N.D. Ill.). - Type Antitrust, Commodities
- Status Pending
-
Co-lead counsel of a putative class of exchange-based investors alleging monopolization and manipulation of Chicago Board of Trade soft red winter wheat futures contracts in violation of federal antitrust and commodity exchange laws.
-
Name
In re JPMorgan Treasury Futures Spoofing Litigation,
No. 20-cv-03515 (S.D.N.Y.). - Type Antitrust, Commodities
- Status Settled
-
Lead counsel in an antitrust case alleging that J.P. Morgan unlawfully and intentionally manipulated U.S. Treasury Futures or Options on U.S. Treasury Futures traded on United States-based exchanges, including but not limited to the Chicago Mercantile Exchange, including its subsidiary the Chicago Board of Trade, during the Class Period in violation of the Commodity Exchange Act, 7 U.S.C. §§ 1, et seq. (the “CEA”) and the common law. The case resulted in a settlement of $15.7 million.
-
Name
Anonymous, et ano. v. Moody's Corporation,
No. 103997/2012 (N.Y. Sup. Ct.). - Type False Claims Act, Tax Fraud, Whistleblower
- Status Settled
-
We obtained an $8.5 million award – the largest-ever settlement in a declined New York State False Claims Act case – for a whistleblower in a groundbreaking case against Moody's and others under the New York State False Claims Act. The litigation brought to light a multi-year, multi-million-dollar tax fraud scheme executed by Moody’s and its consultants wherein the company repeatedly underpaid city and state taxes by maintaining a sham insurance corporation as a subsidiary. KM was successful both before the trial court as well as on appeal before the New York City First Department. Our client received an award of 30% of the $8.5 million recovery.
-
Name
In re Foreign Exchange Benchmark Rates Antitrust Litigation,
No. 13-cv-07789 (S.D.N.Y.). - Type Antitrust, Commodities
- Status Settled
-
Special fiduciary representation for the exchange-based class for a putative class of participants who traded futures and options in the FX market. The case has already resulted in partial settlements of more than $2.3 billion.
-
Name
In re LIBOR-Based Financial Instruments Antitrust Litigation,
No. 11-md-02262 (S.D.N.Y.). - Type Antitrust, Commodities
- Status Settled
-
KM acted as court-appointed co-liaison counsel for all class actions in the multi-district litigation and co-lead counsel for exchange-based class in the high-profile In re Libor-Based Financial Instruments Antitrust Litigation and FTC Capital GMBH et al. v. Credit Suisse Group AG et al. alleging the fixing of prices of a benchmark interest rate. The case resulted in settlements totaling $190.45 million, which combined represent the largest recovery in a “futures-only” commodities class action litigation.
News
Law360 has published an article discussing a major positive decision for plaintiffs in In re: Credit Default Swaps Auctions Litigation, 1:21-cv-00606 (D.N.M.), a class action alleging major banks took part in a more than decade-long, multibillion-dollar scheme to manipulate the benchmark prices used to value credit default swap contracts at settlement.
Kirby McInerney is proud to announce that for the second year in a row, The National Law Journal has named partner Karen Lerner one of its 2023 Elite Women of the Plaintiffs Bar, part of The National Law Journal's 2023 Elite Trial Lawyers awards.
Kirby McInerney is proud to announce that partner Karen Lerner has been named to Law360’s Competition Editorial Advisory Board for 2023. The advisory board works together to provide feedback to Law360's editors on coverage, providing expert insight on how best to shape future content.
Kirby McInerney is pleased to announce that New York-based partner Karen Lerner has been named a Fellow of the American Bar Foundation. Established in 1955, The Fellows of the American Bar Foundation is a global honorary society comprised of attorneys, judges, law faculty, and legal scholars and limited to one percent of lawyers licensed to practice in each jurisdiction.
Thomson Reuters’ Super Lawyers has recognized five KM attorneys as New York Metro Super Lawyers and five as Rising Stars.
The law firm of Kirby McInerney LLP is proud to announce that the Hon. Judge Paul A. Engelmayer of the U.S. District Court for the Southern District of New York has granted final approval of its $15.7 million settlement in In re JPMorgan Treasury Futures Spoofing Litig., No. 1:20-cv-03515 (S.D.N.Y.).
Kirby McInerney is proud to announce that The National Law Journal has named partner Karen Lerner one of its 2022 Elite Women of the Plaintiffs Bar, part of The National Law Journal's 2022 Elite Trial Lawyers awards.
Kirby McInerney is proud to announce that partner Karen Lerner has been named to Law360’s Competition Editorial Advisory Board for 2022. The advisory board works together to provide feedback to Law360's editors on coverage, providing expert insight on how best to shape future content.
On October 15, 2020, the Honorable Michael A. Shipp of the United States Court for the District of New Jersey appointed Karen M. Lerner to the Executive Committee in In re Bank of Nova Scotia Spoofing Litigation, 20 Civ. 11059 (D.N.J.). The case originates from the Bank of Nova Scotia’s alleged price manipulation of gold and silver futures contracts traded on the Commodity Exchange, Inc. over the course of several years, which formed the basis of the bank’s recent settlement with the CFTC and the DOJ for $77.4 million.
A New York federal judge on Friday consolidated seven proposed class actions alleging JPMorgan Chase has been illegally spoofing the futures market since 2009 and appointed Lowey Dannenberg PC and Kirby McInerney LLP as interim lead co-counsel.
A Manhattan federal judge appointed law firms Lowey Dannenberg and Kirby McInerney as lead counsel for proposed class action litigation accusing JP Morgan of deceptive trading in the treasury futures markets. In his ruling, U.S. District Judge Paul Engelmayer cited the two firms’ experience litigating large commodities lawsuits, implicitly rejecting an argument by competitors Nussbaum Law Group (NLG) and Kessler Topaz Meltzer & Check that such an appointment would allow “repeat players” to dominate, which has been identified as a problem by some courts.
A Spanish attorney and officials with an international legal nonprofit told a D.C. federal court on Friday they struck a deal to settle claims that board members blocked him from assuming his duties as the organization's president after he was elected.
The exchange-based investor class, represented by attorneys at Kirby McInerney LLP and Lovell Stewart Halebian Jacobson LLP, won initial approval of a $187 million settlement with Deutsche Bank, JPMorgan and five other big banks in a complex, multidistrict case claiming that the banks rigged the London Interbank Offered Rate benchmark.
Kirby McInerney filed a response in support of interim lead counsel motion highlighting the firm’s experience and rigorous investigation regarding the direct impact on proposed class members in both the bitcoin and bitcoin related futures markets.
One of the biggest names in crypto has joined in an ongoing argument about who will lead the class-action suit against Bitfinex and its affiliates over alleged market manipulation leading to Bitcoin’s 2017 bull run.
Kirby McInerney filed a motion for interim lead counsel in the recently consolidated case in the Southern District of New York, highlighting the firm’s in-depth pre-filing investigation of market participants in consultation with experienced experts.
The Southern District of New York consolidated a case brought by Kirby McInerney and three others that all concern the manipulation of Bitcoin prices by cryptocurrency companies, costing investors hundreds of billions of dollars.
If Bitfinex and Tether thought their problems would just fizzle out, they’re discovering that luck’s not on their side. According to an update provided by The Block, the two individuals behind a lawsuit accusing the duo of manipulating the price of Bitcoin have updated the suit and are pushing forward with their claims. The amended suit was entered only about a month after the plaintiffs had stated that they wouldn’t be making any changes.
Moody’s has reached a settlement with New York-based law firm Kirby McInerney after it was accused of underpaying New York State and New York City business taxes between 2002 and 2014. Moody’s is alleged to have mischaracterised its income as premiums to its captive, Moody’s Assurance Company (MAC).
A Minnesota federal court ruled Wednesday that some of the country’s largest meatpacking companies, including Tyson and Cargill, will now face consolidated allegations of colluding to drive down prices of cattle used for beef production.
Up next on Judge Buchwald’s docket is the distribution agreement of $182 million worth of deals the exchange-based plaintiffs struck with Bank of America, Barclays, Citibank, Deutsche Bank, HSBC and JP Morgan.
Charles Schwab Corp. and investors in financial instruments tied to the London Interbank Offered Rate on Friday urged the Second Circuit to reinstate claims against a slew of banks over their alleged manipulation of the benchmark, arguing they have proper antitrust standing and that the litigation belongs in U.S. federal courts.
A Manhattan federal judge on Friday approved a $182.5 million settlement between JPMorgan Chase & Co., Citigroup and investors who accuse the two megabanks of rigging a key euro rate, signing off also on a roughly $36 million haul for plaintiffs’ firms that brought the antitrust class action.
Kirby McInerney LLP has obtained a groundbreaking appellate decision against Moody’s Corporation, certain of its affiliates, and Marsh & McLennan Companies, Inc. under the New York State False Claims Act.