Securities Expert Witness

Three Decades of Securities Expertise

1,700+ retentions. 750+ testimonies. 42+ states. Board Member and EVP of a major Wall Street firm.

John D. Maine, Securities Expert Witness
Trusted by Leading Law Firms
Davis Polk & Wardwell
Kirkland & Ellis
Latham & Watkins
Simpson Thacher
Morgan Lewis
DLA Piper
Jones Day
Greenberg Traurig
WilmerHale
Proskauer Rose
Davis Polk & Wardwell
Kirkland & Ellis
Latham & Watkins
Simpson Thacher
Morgan Lewis
DLA Piper
Jones Day
Greenberg Traurig
WilmerHale
Proskauer Rose

Why Attorneys Choose John

750+ Cross Examinations (and counting)

Deposition, arbitration, and trial testimony across 42+ states in FINRA, AAA, state, and federal forums.

Board-Level Perspective

Board Member and Executive Vice President of a major Wall Street firm.

Objectivity Through Experience

Retained by both plaintiff and defense counsel. Opinions are grounded in the facts and documents of each case, and they hold up under scrutiny.

Preparation That Shows

Every case is prepared as if reputation depends on it.

Clarity Without Condescension

Complex securities concepts made understandable to judges, juries, and panels without talking down. The ability to educate while persuading is what separates good experts from great ones.

Constantly Evolving Practice

Current on evolving regulations, market structures, and compliance requirements.

1,700+
Total Retentions
750+
Testimonies Given
42+
States Covered
26
Years on Wall Street

Numbers That Mean Something

In securities litigation, credentials matter, but track record matters more. With over three decades as an expert witness and more than a quarter century rising from stockbroker to Board Member at a major Wall Street firm (Smith Barney, now Morgan Stanley Wealth Management), John brings perspective that can't be learned from textbooks.

Areas of Expertise - Representative Sample

Comprehensive securities knowledge spanning traditional brokerage disputes to complex financial instruments.

Breach of Fiduciary Duty

Churning & Excessive Trading

Employee Disputes: Forgivable Notes, Termination, Defamation & Contracts

ETFs, MLPs & Complex Products

Inter-Firm Disputes, Predatory Hiring & Unfair Competition

Margin Accounts

Misrepresentation

Registered Investment Advisor Issues

Suitability

Supervisory Failures

Unauthorized Trading

Variable Annuities

…Among Others

Download the CV for a more complete list.

Expert Background

Answers to the questions counsel needs before retention.

John holds a B.A. from Dartmouth College and has completed extensive industry training and certifications. He held Series 7, 63, 65, and 24 registrations during his Wall Street career, and served as a Registered Principal. His 26-year career culminated as Board Member and Executive Vice President of Smith Barney (now Morgan Stanley Wealth Management).

Over 1,700 retentions across more than 30 years as an expert witness. These include matters for major national firms, regional practices, and individual practitioners representing both plaintiffs and defendants.

Matters involving churning and excessive trading, suitability, unauthorized trading, misrepresentation, breach of fiduciary duty, supervisory failures, margin accounts, variable annuities, registered investment advisor issues, complex products such as ETFs and MLPs, inter-firm disputes, and employee disputes, among others.

Over 750 testimonies including depositions, arbitration hearings, and trial testimony. Experience across 42+ states in FINRA arbitration, AAA arbitration, state court, and federal court proceedings. This extensive experience means no surprises under cross-examination.

  • State and Federal Courts
  • FINRA Arbitration Proceedings
  • The American Arbitration Association
  • JAMS
  • SEC Disciplinary Proceedings
  • SRO Disciplinary Hearings
  • Mediations and settlement conferences

Representative Clients

A selection of the law firms that have retained John as a securities expert.

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