How Insider Trading Law Works—and Why It's Expanding

What Counts as Insider Trading

Insider trading is one of the most serious offenses in financial law, yet no single federal statute explicitly defines it. Instead, enforcement rests on Section 10(b) of the Securities Exchange Act of 1934 and the SEC's Rule 10b-5, which broadly prohibit fraud and deception in connection with securities transactions.

In practice, illegal insider trading occurs when someone buys or sells a security while possessing material nonpublic information (MNPI) — facts a reasonable investor would consider important that have not yet been disclosed to the public. The trader must also breach a duty of trust or confidence owed to the source of that information.

The Four Legal Elements

Federal courts require prosecutors to prove four elements for an insider trading conviction:

• Breach of duty: The trader violated a fiduciary duty or relationship of trust and confidence.
• Material information: The information would matter to a reasonable investor making a decision.
• Nonpublic status: The information was not available to the general investing public at the time of the trade.
• Scienter: The trader acted knowingly or recklessly, not by accident.

Crucially, liability extends far beyond corporate boardrooms. The SEC has successfully prosecuted officers, directors, employees, family members who received tips, and even government employees who traded on confidential information obtained through their work.

Two Competing Legal Theories

Courts recognize two main theories for establishing insider trading liability. The classical theory applies to corporate insiders — officers, directors, and major shareholders — who trade their own company's stock on confidential information, violating a duty owed directly to shareholders.

The misappropriation theory, upheld by the Supreme Court in United States v. O'Hagan (1997), casts a wider net. It holds that anyone who misappropriates confidential information from any source and trades on it can be guilty, even with no connection to the company whose securities are traded. This theory transformed enforcement, enabling prosecution of lawyers, bankers, consultants, and others who encounter MNPI in their professional roles.

Penalties Are Severe

Congress has steadily increased the consequences. Under the Insider Trading and Securities Fraud Enforcement Act of 1988 and subsequent amendments, violators face up to 20 years in prison and criminal fines of up to $5 million for individuals. Civil penalties can reach three times the profit gained or loss avoided.

History shows these are not empty threats. Hedge fund manager Raj Rajaratnam received 11 years in prison and forfeited $53.8 million. Former Enron president Jeffrey Skilling was sentenced to 24 years. Even Martha Stewart served five months for obstructing an investigation into her sale of ImClone shares based on a broker's tip.

Expanding Into New Markets

Traditionally, insider trading law focused on stocks, bonds, and options. That changed as new financial instruments emerged. The Commodity Futures Trading Commission (CFTC) now applies similar anti-fraud rules — under CEA Section 6(c)(1) and Regulation 180.1, modeled directly on the SEC's Rule 10b-5 — to derivatives markets, including futures, swaps, and event contracts on prediction platforms.

In early 2026, the CFTC issued its first formal advisory on insider trading in prediction markets, confirming that the misappropriation theory applies to event contracts. The agency signaled it will prosecute anyone who trades on misappropriated information with the required intent — regardless of whether the market involves stocks or political event contracts.

This expansion reflects a broader legal principle: wherever money changes hands based on asymmetric access to confidential information, the law is likely to follow. As new asset classes and trading platforms proliferate, the century-old framework built for Wall Street continues to stretch — raising fresh questions about where the boundaries of insider trading ultimately lie.