About Jon

Enhancing the efficiency and effectiveness of legal services

Jon Hackbarth is the national chair of the Quarles Securities Litigation and Enforcement Practice Group and has been repeatedly recognized by Best Lawyers in America® and Wisconsin Super Lawyers® for his litigation practice. Jon also represents a wide array of clients in connection with shareholder and business disputes, and leads a team of attorneys representing micromobility providers in connection with permit, insurance and product liability issues.

Jon works with his clients to:

  • Enhance the quality of their legal services.
  • Streamline their legal processes.
  • Decrease their overall legal spend.

Having started his career working in the legal department of a large corporation, Jon understands how outside counsel can best partner with clients — learning their businesses and systems, developing strategies aligned with their business goals and putting in place the right teams and processes to achieve their desired results in a lawful, cost-effective manner.

Experience in Action

  • Successfully defending corporations, financial advisors, broker-dealers and individuals against investigations, subpoenas and enforcement actions brought by the U.S. Securities and Exchange Commission (SEC), the Financial Industry Regulatory Authority (FINRA) and state securities regulators.
  • Representing FINRA industry members in industry disputes over allegations of U5 defamation, expungement, raiding, theft of trade secrets and violations of noncompete and nonsolicitation agreements.
  • Representing FINRA industry members in customer disputes over allegations of unsuitability, breach of fiduciary duty, misrepresentation, securities fraud and negligence.
  • Defending clients against class-action lawsuits involving claims over securities fraud, proxy disclosures and diminution in stock value.
  • Representing clients in lawsuits over shareholder rights and corporate control.
  • Representing clients against direct and derivative claims over securities fraud and state and federal laws governing the securities industry.
  • Representing financial advisors seeking to expunge U4 and U5 disclosures related to customer complaints and termination disclosures.


  • Obtaining multiple temporary restraining orders prohibiting clients' former representatives from soliciting their former customers.
  • Obtaining a favorable resolution of a multiyear securities investigation brought by the SEC and multiple states securities agencies.
  • Successfully defending a broker-dealer against an expungement and defamation action.
  • Dismissing a shareholder class action lawsuit seeking to enjoin a merger and obtaining sanctions against the plaintiffs.
  • Obtaining a complete defense award in a FINRA arbitration seeking seven-figure damages for alleged misrepresentations made concerning an investment.
  • Obtaining a no-action letter on a client's behalf who was the subject of a multiyear SEC investigation.
  • Obtained dismissal of a corporate credit union’s lawsuit alleging common law and constitutional violations, filed against a large credit union in the Eastern District of Wisconsin.
  • Successfully defended a hedge fund and representatives thereof against Section 10b-5 and other fraud claims.
  • Dismissed a securities lawsuit filed against a hedge fund in New York State Court, blocking plaintiff’s attempt to amend after dismissal, and subsequently securing dismissal of a related lawsuit filed in federal court.
  • Obtained dismissal of a Section 16(b) lawsuit seeking short-swing profits filed against a hedge fund in the Southern District of New York.
  • Successfully expunged disclosures from financial advisors’ FINRA regulatory records.

Professional Recognitions

  • Wisconsin Super Lawyers® "Rising Stars" (Securities Litigation)
  • Best Lawyers in America® (2022-2024: Litigation - Securities)

Professional & Civic Activities

  • Appointed as a commissioner to the City of Milwaukee Standards and Appeals Commission
  • American Bar Association, Business Law Division, Business and Corporate Litigation Committee, member
  • Milwaukee Young Lawyers Association, board member
  • Marquette University High School Alumni Association, board member
  • State Bar of Wisconsin, member

News & Insights


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