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William E. Walsh

How to properly pronounce this name:
Partner
Chicago
T.
312.517.9543
liamE
My mission is to advocate for clients as they navigate regulatory complexity so they can thrive in the financial markets with confidence.
My mission is to advocate for clients as they navigate regulatory complexity so they can thrive in the financial markets with confidence.

Bill represents clients across a wide range of industries in litigation and regulatory matters. He has extensive knowledge of global securities and commodities markets. As a former regulator, he understands the challenges market participants face in navigating the complex regulatory environment. He is an accomplished commercial litigator, with a track record of success in matters related to securities fraud, market manipulation, auditor liability, and high-frequency trading. Bill represents clients in SEC, CFTC, and exchange investigations and prosecutions.

Prior to joining Benesch, Bill spent four years in market regulation at American global markets company CME Group Inc., the world’s largest financial derivatives exchange. As Senior Enforcement Counsel, he prosecuted rule violations, conducted hearings before exchange disciplinary panels, and administered the exchange arbitration process. Bill’s experience at CME Group provided him valuable perspective that informs the advice he provides to clients in the complex litigation, investigative, and regulatory matters he now handles in private practice.

Bill has served as an adjunct professor at the Loyola University Chicago School of Law, teaching Securities Regulation.     

Broad Litigation Experience

Bill is a seasoned litigator, with experience in various forums, including federal and state courts, administrative agency proceedings, and arbitration. In financial markets, he has experience with a broad range of financial products and asset classes, including securities, agricultural products, currencies, energy, interest rates, metals, stock indexes, and digital assets.

Prosecutorial Experience

As Senior Enforcement Counsel in CME Group’s Market Regulation Department, Bill investigated and prosecuted rule violations on CME Group Exchanges related to matters such as disruptive trading and messaging, spoofing, trading algorithms and system malfunctions, wash trades, position limit violations and non-competitive trading.

Digital Assets Expertise

Bill has written and advised on numerous issues surrounding cryptocurrency and coin offerings, including ongoing developments in regulation of digital assets by the SEC, CFTC and other regulators.

Representative Experience

  • Represented a major stock exchange in class action alleging fraud in high frequency trading, securing dismissal on summary judgment.
  • Represented international bank in class action alleging antitrust and CEA violations in CDOR rate-setting, defeating claims against client on motion to dismiss.
  • Represented a “Big Four” accounting firm in auditor liability seeking over $3 billion in damages. Secured a directed verdict in favor of the accounting firm following 103 days of arbitration testimony and argument.
  • Represented FX dealer in five-day NFA arbitration involving customer allegations of improper margin liquidation. Resulted in unanimous award rejecting claims.
  • Represented a leading broker-dealer in defense of SEC allegations of Reg SHO violations.
  • Representing a global election technology company in a defamation suit seeking over $2 billion against various news organizations.
  • Litigation
  • Accounting & Financial Reporting Litigation
  • Defamation Litigation
  • Securities & Commodities Litigation
  • White Collar, Government Investigations & Regulatory Compliance
  • Artificial Intelligence (AI)
  • Georgetown University Law Center, J.D.
  • University of Southern California, B.A.
  • Illinois
  • California
  • U.S. District Court for the Central District of Illinois
  • U.S. District Court for the Northern District of Illinois
  • U.S. Court of Appeals for the Seventh Circuit
  • Judicial Evaluation Committee, Chicago Bar Association
Articles and Presentations
September 25, 2025
Cryptocurrency Summer 2025 Roundup: What You Missed & What’s Ahead
March 21, 2025
What the Future May Hold for Crypto Asset Litigation and Regulation
June 8, 2023
CFTC Issues Staff Advisory Letters on DCO Regulation: Prime Brokerage Arrangements and Digital Assets

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News
November 4, 2025
Business Insider Quotes Benesch Partner William Walsh in High-Profile Crypto Fraud Trial Coverage
December 18, 2023
William E. Walsh mentioned in Crain's Chicago People on the Move
October 17, 2023
William E. Walsh mentioned in Law360 article | "Benesch Adds Financial Litigation Partner in Chicago"

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