A former federal prosecutor and Chief Trial Counsel of the Securities and Exchange Commission, Thomas A. Zaccaro focuses his practice on civil, commercial and criminal litigation in state and federal courts with a special emphasis on defending corporations and executives in government investigations and other criminal and regulatory proceedings. Described by a client to Chambers as “a smart, savvy attorney that is the right kind of aggressive,” his representations also include general securities litigation, class actions, and shareholder derivative suits.
Prior to joining Hueston Hennigan, Mr. Zaccaro was a partner at Paul Hastings in Los Angeles where he represented public companies and their officers and directors, accounting firms and investment advisors in SEC and DOJ investigations and private civil litigation, and recently secured a jury trial victory in SEC v. Moshayedi (insider trading).
For over 10 years, Mr. Zaccaro worked in government most recently as Chief Trial Counsel of the SEC’s Pacific Regional Office, where he was responsible for the management and supervision of all enforcement litigation conducted within the Pacific Region. Mr. Zaccaro also served as an Assistant U.S. Attorney for the Southern District of New York and as a Trial Attorney at the Department of Justice, Organized Crime and Racketeering Section.
Mr. Zaccaro has also been an Adjunct Professor in Securities Regulation at the University of Southern California Gould School of Law since 2013.
Experience
Civil Securities Litigation
Represented the CEO of a NASDAQ-listed company in an insider trading case involving omissions in connection with a secondary offering. Obtained a defense verdict after trial. The Daily Journal recognized the victory as a Top Defense Verdict.
Representing the officers and directors of a NYSE-listed company in securities litigation involving allegations of omissions in the registration statement and prospectus for a secondary offering.
Representing the former CEO and chairman of a NASDAQ-listed company in a securities class action and shareholder derivative cases related to allegations of misrepresentations and omissions in SEC filings.
Representing the former CEO of a NYSE-listed company in a securities class action and shareholder derivative cases related to allegations of misrepresentations and omissions in SEC filings and in connection with a secondary offering.
Represented a NASDAQ-listed company and its officers and directors in a securities class action and shareholder derivative cases related to alleged omissions in SEC filings. The cases were dismissed at the pleadings stage.
Represented a NASDAQ-listed corporation in shareholder derivative action alleging fraudulent proxy disclosures concerning executive compensation. Case was dismissed at pleadings stage.
Represented a former PwC audit partner in securities litigation involving omissions and misrepresentations in SEC filings.
Represented a NASDAQ-listed company and its officers and directors in shareholder derivative cases related to stock option backdating. The case settled after a motion to dismiss was granted.
Represented the former CFO of a NASDAQ-listed company in a securities class action and shareholder derivative cases related to omissions in SEC filings.
Obtained a dismissal with prejudice upon a motion to dismiss on behalf of a California-based electronics retailer in a commercial fraud case filed by several Korean banks.
Obtained a dismissal with prejudice upon a motion to dismiss on behalf of the independent directors of the American Funds in a shareholder derivative action.
Regulatory and White Collar Matters
Obtained a sweeping victory for Joshua Abrahams, a former PwC auditor, when the SEC voluntarily dismissed an administrative action charging Abrahams in connection with a Mattel audit that later resulted in a $109 million restatement.
Representing a publicly traded American multi-brand restaurant operator in a combined DOJ and SEC investigation.
Successfully defended former CEO of sTec, Inc. in jury trial victory against the SEC in an insider trading case.
Represented an auditing firm and audit partner in an SEC investigation and private litigation arising from audits of a company charged by the SEC with offering fraud.
Represented a NASDAQ-listed biopharmaceutical corporation and its officers in SEC and DOJ investigations regarding potential disclosure fraud. Both the SEC and DOJ terminated their investigations without any enforcement actions or criminal prosecutions.
Represented a NASDAQ-listed corporation and its officers in SEC and DOJ investigations regarding potential disclosure fraud.
Served as an expert witness in securities regulation and SEC enforcement topics in numerous cases filed in federal and state courts. Led internal investigation for an investment advisor concerning potential cross-trading violations.
Secured closure without any enforcement proceedings in an investigation of an investment advisor accused by the SEC and CFTC of causing the May 2010 “flash crash.”
Represent numerous directors, officers and employees of public corporations, investment advisers and broker-dealers in SEC and DOJ insider trading investigations.
Represent NYSE- and NASDAQ-listed companies in FCPA investigations conducted by the SEC and the Department of Justice.
Conducted numerous internal investigations on behalf of corporations and their Audit Committees concerning accounting, revenue recognition, disclosure, and various other securities-related issues.
Represented several NYSE- and NASDAQ-listed companies, as well as individual officers and employees, in stock option investigations being conducted by the SEC and the Department of Justice and in related shareholder derivative litigation.
Conducted an internal investigation on behalf the board of an investment advisor following whistleblower complaint of potential personal trading violations.
Conducted an internal investigation on behalf of board of a NASDAQ-listed corporation concerning potential insider trading by an executive officer.
Secured closure without any criminal charges or SEC enforcement proceedings of a CFO of NASDAQ-listed bio-pharmaceutical company in SEC and DOJ investigations concerning disclosure fraud.
Concluded an investigation of management-level employees of a pharmaceutical company without any criminal charges being filed related to DOJ False Claims Act issues.
Obtained closure without any SEC enforcement proceedings on behalf of members of the San Diego City Council in connection with several investigations concerning the City’s disclosures in certain bond offering documents.
Secured closure without any criminal charges or SEC enforcement proceedings for a former CFO of NASDAQ-listed corporation in SEC and DOJ investigations concerning allegations of accounting fraud.
Recognitions
- Enforcement Elite, Securities Docket (2024)
- Litigation Star, Benchmark Litigation
- The Best Lawyers in America (2013-2025)
- Southern California Super Lawyers
- Enforcement 40, Securities Docket (2017)
Activities
Founder and Secretary, Investor Choice Advocates Network
Insights
- 1/1/2025
- Co-host of "SEC Roundup," a bimonthly video series opens in a new tab
- 11/28/2023
- “The SEC’s recent enforcement actions confirm whistleblower protections” opens in a new tab
- 6/6/2022
- “SEC suffers judicial setbacks for administrative hearings” opens in a new tab
- 12/27/2021
- “SEC enforcement looks forward to strong FY2022” opens in a new tab
- 6/30/2021
- “Supreme Court brings clarity to ‘fraud-on-the-market’ theory” opens in a new tab
- 6/8/2021
- “Congress sets sights on insider trading legislation” opens in a new tab
- 4/12/2021
- “Getting SPACs right” opens in a new tab
- 3/2/2021
- “The SEC want to know who’s in your Clubhouse” opens in a new tab