Grant & Eisenhofer Files Securities Class Action Lawsuit Against Canadian Imperial Bank of Commerce and Royal Bank of Canada on behalf of investors in Quantum Biopharma Ltd. Securities

NEW YORK–(BUSINESS WIRE)–On December 19, 2025, Grant & Eisenhofer P.A. filed a class action lawsuit on behalf of Paul Durkacz against the Canadian Imperial Bank of Commerce (“CIBC”) and Royal Bank of Canada (“RBC”), and their broker-dealer subsidiaries (together, the “Defendants”). The action alleges that Defendants defrauded investors by placing and executing manipulative trades designed to artificially deflate the price of Quantum Biopharma Ltd. (“Quantum”) securities.

The action is brought on behalf of all persons who sold securities of Quantum between January 6, 2021 and October 15, 2025, inclusive (the “Class Period”) and were damaged thereby. The action, brought in the United States District Court for the Southern District of New York, is captioned Paul Durkacz v. CIBC World Markets Inc., No. 1:25-cv-10565 (S.D.N.Y.).

CIBC and RBC are Canadian chartered banks whose U.S. subsidiaries are registered with the Securities and Exchange Commission and operate as major market makers, routinely placing and executing securities trades for investors as well as for their own trading accounts.

The complaint alleges violations of Sections 9, 10(b), and 20(a) of the Securities Exchange Act of 1934. Specifically, the lawsuit alleges that throughout the Class Period, Defendants engaged in a manipulative and illegal trading practice known as “spoofing,” which involves submitting and then cancelling buy or sell orders without any genuine intent to execute them. The purpose of these “baiting orders” was to mislead other market participants about the true level of supply and demand for Quantum securities, or about the stock’s price volatility, thereby influencing the market price of Quantum to benefit Defendants’ own trading positions.

Defendants entered thousands of these baiting orders on U.S. stock exchanges to create the false impression that Quantum’s stock price reflected genuine supply-and-demand and volatility dynamics, while simultaneously profiting by, among other things, purchasing Quantum securities at prices artificially depressed by their manipulative and deceptive conduct.

Investors who sold Quantum securities during the Class Period are members of this proposed Class and may be able to seek appointment as lead plaintiff, which is a court-appointed representative of the Class, by complying with the relevant provisions of the Private Securities Litigation Reform Act of 1995 (the “PSLRA”). See 15 U.S.C. Section 78u-4(a)(2)(A)(i)-(vi).

If you wish to serve as lead plaintiff, you must move the Court by no later than February 23, 2026. You do not need to seek to become a lead plaintiff in order to share in any possible recovery. You may also retain counsel of your choice to represent you in this action.

If you wish to discuss this action or have any questions concerning this notice or your rights, please contact Abe Alexander at Grant & Eisenhofer at 646-722-8500, or via email at aalexander@gelaw.com.

Contacts

Media Contact:

Abe Alexander

Grant & Eisenhofer P.A.

Tel.: (646) 722-8500

aalexander@gelaw.com