William E. Mahoney Jr.

William Mahoney


Bill Mahoney is an accomplished trial attorney whose practice is focused on complex business litigation, particularly within the financial services industry. For more than 20 years, Bill has represented financial institutions such as brokerage firms, investment advisers and banks in all manner of disputes, including securities litigation and arbitration, and regulatory investigations and enforcement proceedings. He also regularly represents businesses of all sizes in a wide array of commercial litigation, including employment discrimination and sexual harassment matters, unfair competition and restrictive covenant claims, class actions, copyright infringement and intellectual property matters, and professional liability disputes.

With a pragmatic, value-driven and results-oriented approach to dispute resolution and litigation, Bill has earned the respect of clients and adversaries alike.

Read More


Representative Matters

  • obtained a multimillion-dollar award on behalf of a broker-dealer client against a competing firm for unfair competition
  • represented a brokerage firm in a $25 million auction-rate securities case in federal court, securing a favorable settlement shortly after the jury trial began
  • secured dismissal of a financial advisory firm’s lawsuit against a distressed debt investment firm, in which the plaintiff asserted claims of tortious interference with contract and unfair competition and sought a seven-figure fee
  • secured a jury verdict in favor of a national entertainment franchise in a premises liability matter, following a week-long trial in federal court
  • defended multiple age and religious discrimination claims by former employees against a brokerage firm both in federal court and arbitration, obtaining an award of attorney’s fees against the employee in one matter and securing a settlement in which another employee paid a significant amount to our client
  • represented a national bank in a class action arising out of a municipal debt issuance
  • defended a regional broker-dealer against claims brought by a former broker for fraudulent inducement and related torts
  • defeated unfair labor practice charges brought on behalf of a union against one of the country’s largest veal and lamb processing companies, including the alleged wrongful termination of a pro-union employee, following a two-week hearing before the National Labor Relations Board
  • represented a national computer retailer in a contractual dispute with an Internet service provider that was seeking millions of dollars in damages
Read More


Bar Admissions
  • Pennsylvania
Court Admissions
  • Pennsylvania Supreme Court
  • U.S. Court of Appeals for the Third Circuit
  • U.S. District Court for the Eastern District of Pennsylvania
  • U.S. District Court for the Middle District of Pennsylvania
  • J.D., magna cum laude, Temple University Beasley School of Law
  • M.A., University of Rochester
  • B.A., magna cum laude, La Salle University

  • American Bar Association
  • Board of Managers, Abington YMCA
  • Stradley Ronon Diversity Group

Speaking Engagements

  • Presenter, “After the Election: What to Expect from the New Administration in the Securities Field,” Securities Regulation Committee Meeting
  • Speaker, “The Importance of Expert Witness Research,” Litigation Summit, The Legal Intelligencer
  • Speaker, “FINRA Arbitrations: Tools & Practical Guide for 2016 and Beyond,” The Knowledge Group
  • Panelist, “The Litigation Summit,” The Legal Intelligencer

Read More


  • Pennsylvania Super Lawyers
  • Abington YMCA, Volunteer of the Year
Read More

In The Community

When not practicing law, Bill devotes his time to charitable organizations, having served in the past as the president of the board of directors of the Make-A-Wish Foundation of Philadelphia and Southeastern Pennsylvania.

Bill was named Abington YMCA’s Volunteer of the Year in 2014. He serves on the board of managers of the Abington YMCA and received the award as a “Y Champion for Social Responsibility” based on his leadership of the Abington YMCA Annual giving campaign, among other contributions. The Abington YMCA is part of the Philadelphia Freedom Valley YMCA, which serves more than 140,000 members and 200,000 individuals each year – regardless of age, income or background – to nurture the potential of children and teens, improve the nation’s health and well-being, and provide opportunities to give back and support neighbors.

Read More
Back to top