Insider trading is considered illegal when a person buys or sells a publicly traded security while holding material nonpublic information about it, in breach of a duty to keep that information confidential. The prohibition sits in Section 10(b) of the Securities Exchange Act of 1934 and SEC Rule 10b-5. What confuses most people is that the phrase covers legal conduct too: corporate officers and directors buy and sell their own company’s stock routinely, and those trades are lawful as long as they aren’t driven by confidential information and are properly disclosed. The line between the two versions turns on what the trader knew and what duty they owed when they placed the order.
Material Nonpublic Information
Every illegal insider trading case starts with the same question: was the information material and nonpublic? Both elements have to be present.
“Material” means there’s a substantial likelihood that a reasonable investor would consider the information important when deciding whether to buy or sell. The Supreme Court has framed this as whether the information would significantly change the “total mix” of facts available to the market.1U.S. Securities and Exchange Commission. Staff Accounting Bulletin No. 99 – Materiality A practical shortcut: if the news would move the stock price once announced, it’s almost certainly material. Pending mergers, earnings surprises, major contract wins or losses, regulatory decisions on a new product, and significant leadership changes are the usual examples. The information doesn’t have to be final or precise. Even preliminary merger talks can qualify once they’ve reached a point where a reasonable investor would want to know.
“Nonpublic” means the information hasn’t been released to the market through official channels like press releases, SEC filings, or public conference calls. A rumor on social media doesn’t make something public. Neither does sharing it inside a small group of professionals. Information loses its restricted status only after the investing public has had a reasonable opportunity to absorb it. Until then, anyone who trades on it while owing a duty of confidentiality is exposed.
When Trading by Insiders Is Legal
Officers, directors, and major shareholders trade their own company’s stock regularly, and the vast majority of those trades are entirely legal. Section 16 of the Exchange Act requires these insiders to publicly report their transactions on Forms 3, 4, and 5.2U.S. Securities and Exchange Commission. Insider Transactions and Forms 3, 4, and 5 A Form 4 is due within two business days of a trade, so the market usually learns of insider transactions almost immediately.
The dividing line is what drove the trade. A CEO who sells shares to diversify her portfolio or fund a home purchase is fine. That same CEO selling the day before announcing terrible earnings is not. The transaction itself isn’t the crime. The information behind it is what matters.
Rule 10b5-1 Plans
Insiders who want to trade without constantly worrying about what they might know can set up a Rule 10b5-1 trading plan. These plans work as an affirmative defense by establishing that a trade was arranged before the insider had any material nonpublic information.3U.S. Securities and Exchange Commission. Insider Trading Arrangements and Related Disclosures To qualify, the insider adopts the plan in writing at a time when they aren’t aware of any such information, and the plan has to specify the number of shares, the price, and the trading dates, or use a formula that removes the insider’s discretion. Once in place, the plan can’t be altered based on newly learned information.4eCFR. 17 CFR 240.10b5-1 – Trading on the Basis of Material Nonpublic Information
The SEC tightened these rules after concerns that insiders were gaming them. Directors and officers now face a cooling-off period of at least 90 days after adopting a plan before any trade can execute, and they must certify in writing that they aren’t aware of material nonpublic information and aren’t using the plan to evade trading restrictions. Insiders generally can’t maintain multiple active plans for the same class of securities at once, and single-trade plans are limited to one per 12-month period. Modifying an existing plan’s price, amount, or timing restarts the cooling-off clock, because the SEC treats a material change as a new plan.
Who Can Be Charged
Federal law reaches further than most people realize. Several categories of people can be liable for insider trading:
- Corporate insiders — officers, directors, and any employee who accesses confidential information through their role at the company. They owe a fiduciary duty to shareholders that bars them from exploiting nonpublic information for personal gain.
- 10% beneficial owners — anyone who directly or indirectly owns more than 10% of any class of a company’s registered equity securities is treated as a statutory insider with the same reporting duties and trading restrictions as officers and directors.5eCFR. 17 CFR 240.16a-2 – Persons and Transactions Subject to Section 16
- Constructive insiders — outside professionals who gain access to confidential data through their work for a company, including attorneys, investment bankers, accountants, and consultants. Courts treat them as insiders for the duration of that access.
- Tippees — anyone who receives material nonpublic information from an insider and trades on it, even if they have no connection to the company.
You don’t need a badge, a title, or a contract with the company to face liability. If you trade on confidential information that you knew, or should have known, came from an insider source, you’re exposed.
Tipper-Tippee Liability and the Personal Benefit Test
When an insider passes confidential information to someone else who trades on it, both the tipper and the tippee can be charged. But the law doesn’t automatically make every leak illegal. The Supreme Court held in Dirks v. SEC that the tipper must receive some personal benefit from sharing the information for liability to attach. That benefit can be financial, reputational, or even the satisfaction of making a gift to a friend or family member.
The bar for what counts as a benefit is low. In Salman v. United States, the Court confirmed that simply giving confidential information to a close relative who trades on it is enough; the tipper doesn’t need cash or any tangible reward in return.6Justia U.S. Supreme Court. Salman v. United States, 580 U.S. ___ (2016) The Court’s reasoning: gifting inside information to a trading relative is the same as trading and handing over the profits.
The tippee’s liability depends on knowledge. The recipient must have known, or should have known, that the information was confidential and that the tipper was breaching a duty by sharing it. Liability follows the information down a chain of recipients. If your coworker heard from her brother who heard from his wife the CFO, and you trade on it knowing the information came from inside the company, you can be charged.
Classical and Misappropriation Theories
Courts have developed two separate frameworks for insider trading cases, and they target different relationships.
The Classical Theory
The classical theory is the straightforward scenario most people picture. A corporate insider trades their own company’s securities using confidential information they learned on the job. The violation is a breach of the fiduciary duty the insider owes to the company’s shareholders. By trading on information those shareholders don’t have, the insider is cheating the people on the other side of the trade. The legal foundation is Section 10(b) of the Exchange Act, which prohibits deceptive conduct in connection with securities transactions.7Office of the Law Revision Counsel. 15 U.S. Code 78j – Manipulative and Deceptive Devices
The Misappropriation Theory
The misappropriation theory catches everyone else. It applies when someone who isn’t a corporate insider misuses confidential information to trade. In United States v. O’Hagan, the Supreme Court held that a person who trades using confidential information obtained in breach of a duty owed to the source of that information, rather than to the company whose stock was traded, commits securities fraud.8Cornell Law Institute. United States v. O’Hagan, 521 U.S. 642
A classic example: an attorney at a law firm learns that a client’s company is about to acquire another business, then buys stock in the target. He owes no duty to the target’s shareholders, but he does owe a duty of confidentiality to his firm and its client. By secretly using that information, he defrauds the source. This theory closed a major loophole, because without it, anyone outside a company could trade freely on stolen confidential data.
Shadow Trading
The SEC has been pushing the misappropriation framework further with a theory called shadow trading: using confidential information about one company to trade the stock of a different company, typically a competitor or industry peer whose price would predictably move on the same news. The SEC tested this in SEC v. Panuwat. A Medivation employee learned that Pfizer was about to acquire his employer and purchased call options in Incyte Corporation, a comparable company whose stock jumped about 8% after the acquisition announcement. A jury found him liable in 2024.9U.S. Securities and Exchange Commission. Matthew Panuwat Litigation Release Whether courts will broadly embrace the theory remains an open question, but the verdict shows the SEC has a viable path. Trading in an “adjacent” company is not a safe workaround.
Short-Swing Profits Are a Separate Rule
Alongside the fraud-based rules, Section 16 of the Exchange Act imposes a strict, automatic penalty on insiders who buy and sell, or sell and buy, their company’s stock inside a six-month window. Any profit from that kind of short-swing transaction must be returned to the company, regardless of whether the insider actually used nonpublic information.10Office of the Law Revision Counsel. 15 U.S. Code 78p – Directors, Officers, and Principal Stockholders The rule applies to officers, directors, and 10% beneficial owners. Intent doesn’t matter. If a director buys in January and sells at a profit in April, the company (or any shareholder, if the company doesn’t act) can sue to recover the gain. The point of the rule is its simplicity: rather than proving misuse of confidential information, it bans the short-term round trip altogether.
Civil and Criminal Penalties
Insider trading is enforced on two tracks, and the government frequently pursues both at once against the same person.
On the SEC side, the agency can require disgorgement of all profits earned or losses avoided, and can seek a civil monetary penalty of up to three times that amount.11Office of the Law Revision Counsel. 15 U.S. Code 78u-1 – Civil Penalties for Insider Trading Someone who made $500,000 on an illegal trade could owe the $500,000 back plus another $1.5 million in penalties. The SEC can also seek injunctions barring the person from serving as an officer or director of a public company. Firms whose compliance failures allowed the trading can themselves be penalized up to the greater of $1 million or three times the profit or loss involved.
On the criminal side, the Department of Justice handles prosecutions. A willful violation of the Exchange Act carries up to 20 years in federal prison and fines of up to $5 million for individuals; entities can be fined up to $25 million per violation.12GovInfo. 15 U.S. Code 78ff – Penalties Those are ceilings, not typical sentences, but federal prosecutors and judges have shown they’re willing to impose substantial prison time, particularly in cases involving hedge fund managers or repeat conduct.