John G. Moon

A former SEC branch chief and enforcement attorney, and a former federal prosecutor of financial crimes for the U.S. Department of Justice, litigator John Moon brings unrivaled skill and perspective in representing clients in securities regulatory matters, complex civil litigation, and white-collar criminal defense cases.

John represents financial institutions, public companies, and executives in wide-ranging and game-changing commercial litigation, internal investigations, and in civil and criminal investigations and proceedings brought by grand juries, the SEC, DOJ, CFTC, FINRA and state governmental entities. John has successfully represented institutions and individuals caught up in some of the largest financial fiascos of this century: FTX, Enron, S.A.C. Capital and Madoff. His civil litigation experience also includes a focus on structured finance, securitizations, and proposed multibillion-dollar “private label” RMBS settlements. Further, he has represented financial institutions in civil disputes involving CDOs, CLOs and capital markets.

A recognized authority in his field, John is often quoted by leading national publications and news outlets such as PBS Frontline, Vanity Fair, The New York Times, Law360, USA Today, The Philadelphia Inquirer, and The Washington Post, which have covered many of his high-profile wins over the years.

Before joining Olshan, in addition to his roles at the SEC and as a DOJ prosecutor, John was a partner in the Financial and Securities Industries Practice at a New York-based law firm. He also served as an executive director of litigation for the Americas at UBS Investment Bank in New York and as a Principal Consultant in the Banking, Finance and International Group of PricewaterhouseCoopers LLP.

During his tenure at the DOJ, John received a special achievement award from the U.S. Attorney General. Most recently, John was appointed Receiver by the Delaware Court of Chancery to run a high-tech public company.

  • Appellate Litigation: Macquarie Infrastructure Corp. v. Moab Partners, Docket No. 22-1165 (U.S. Supreme Court writ of Certiorari granted Sept. 29, 2023) (Rule 10b-5); Packer v. Raging Capital Mgmt., LLC, No. 19-2703 (2d Cir. 2020) (Short Swing Profit Rule); United States v. John Edward Hayes, Jr., et al., 40 F.3d 362 (11th Cir. 1994) (wire fraud, interstate transportation of stolen property, and conspiracy).
  • Structured Finance Litigation: UBS Securities LLC et al. v. Highland Capital Management, LP et al., Index No. 650097/2009 (Architect of collateralized debt obligation case resulting in $1 billion judgment on behalf of UBS in 2019).
  • RMBS litigation: In re Residential Capital LLC, 12-12020-mg (Bankr. S.D.N.Y. 2012) (successfully represented financial institution revising allocation formula distributing $8.7 billion allowed claim); In the Matter of the Application of the Bank of New York Mellon, Index No. 651786 (N.Y. Sup. 2011), prevailed after a nine-week trial in proposed $8.5 billion RMBS “private label” settlement).
  • FINRA arbitration: Jones v. Cantella & Co., Inc., No. 18-00166 (2019) (successfully tried complex case resulting in a $0 award on claims that broker-dealer violated trading restrictions on common stock spun off from a corporate combination). 
Financial accounting:
  • SEC v. Gemstar-TV Guide International, et al., CV-03-4376NM (C.D. Cal. 2004).
  • In the Matter of USA Detergents, Inc., SEC Rel. Nos. 33-8112, 34-46225, AAE-1597 (2002).
Insider trading, broker-dealer operations, and market manipulation:
  • United States v. Charles H. Howard III, Cr. No. 92-74-01-D (D.N.H. 1992) (conspiracy to commit securities fraud, bank fraud, and bank bribery in connection with the failure of Thomson McKinnon Securities Inc.).
Civil litigation involving stock loan:
  • Nomura Securities International, Inc. v. E*Trade Securities, Inc., 2003 WL 22058235 (S.D.N.Y.) (contract and fraud claims and counterclaims involving a $41 million stock loan).
Operations of an investment adviser:
  • SEC v. Steadman Management Corp. et al., 1991 WL 30794 (D.D.C. Feb. 27, 1991), revd in part, 967 F.2d 636 (D.C. Cir. 1992).
Asset forfeiture, and parallel SEC and grand jury investigations:
  • SEC v. Health South Corporation and Richard M. Scrushy, CV-03-J-0615-S (N.D. Ala. 2003).
Mutual fund disclosure:
  • In re Mutual Funds Investment Litigation, 04-MDL-1586 (D. Md. April 20, 2011) (MDL regarding alleged mutual fund timing and late trading).
GAAP interpretation and off-balance sheet accounting:
  • In the Matter of PNC Financial Services Group, Inc., SEC Rel. Nos. 33-8112, 34-46225, AAE-1597 (2002).


Speaking Engagements

Panelist: ACI's 8th National Forum on Controlling Litigation Costs (New York 2013)

Frequent speaker at conferences concerning regulatory and securities issues

Panelist: Stafford Publications, In-House Counsel's Evolving Duties (New York 2011)

Panelist: ACI, Forum on Reducing Legal Costs (Philadelphia 2009, 2010)

Co-Chair: ACI, Advanced Forum on Securities Litigation (New York 2009, 2010)


  • Former Officer and Member of the Board of Managers, Harvard Club of New York City
  • Former Trustee, Village of Tuxedo Park
  • Former Board of Education Member, Tuxedo Union Free School District


LL.M., Harvard Law School

J.D., Washington College of Law

  • Law Review Contributing Author
  • Dean’s Fellow

B.A. magna cum laude, Dickinson College

  • Dana Scholar
  • Recipient, Charles M. Nisbet Memorial Scholarship.


  • New York
  • District of Columbia
  • Pennsylvania (inactive)
  • U.S. Court of Appeals for the Second Circuit
  • U.S. District Court for the Southern District of New York
  • U.S. District Court for the Eastern District of New York
  • U.S. District Court for the Eastern District of Pennsylvania
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