--- title: "Most insider trading is legal. What makes the rest a crime" description: "Executives buy and sell their own company's shares constantly and lawfully, which is why you see the headlines. The SEC's definition of the illegal version turns on three elements, and the one that decides most cases is not the information but the duty." category: "Markets" category_url: https://boursel.com/category/markets author: "Kenji Nakamura" published: 2026-07-20T19:14:00.000Z updated: 2026-07-20T19:14:00.000Z canonical: https://boursel.com/article/most-insider-trading-is-legal-what-makes-the-rest-a-crime tags: ["regulation", "sec", "securities-law", "governance"] --- # Most insider trading is legal. What makes the rest a crime Executives buy and sell their own company's shares constantly and lawfully, which is why you see the headlines. The SEC's definition of the illegal version turns on three elements, and the one that decides most cases is not the information but the duty. "Insider trading" is used loosely to mean any trading by someone who works at a company. That is not what it means legally, and the gap causes a lot of confused reading of the news. Corporate officers and directors trade their own company's stock routinely and legally. They receive shares as compensation, they diversify, they pay tax bills. What they must do is report it, which is why those trades are visible and generate headlines. Visibility is not illegality. ## The SEC's definition, and its three parts The [SEC defines](https://www.investor.gov/introduction-investing/investing-basics/glossary/insider-trading) illegal insider trading as "buying or selling a security, in breach of a fiduciary duty or other relationship of trust and confidence, on the basis of material, nonpublic information about the security." Three elements have to be present together. **Material.** The information must be important enough that a reasonable investor would want it before deciding to buy or sell. A pending merger, an earnings figure well outside expectations, the failure of a major trial, the loss of a dominant customer. Trivia about the company does not qualify however secret it is. **Nonpublic.** It has not been disclosed to the market. Information does not become public because a few hundred people inside a company know it. **In breach of a duty.** This is the element that decides cases, and the one most often missed. ## Why the duty is what matters Trading on material nonpublic information is not, by itself, the offense. The offense requires that obtaining or using the information broke an obligation of trust. A chief financial officer owes that duty to the company and its shareholders. So does the law firm handling its merger, the bank advising on it, the printer producing the documents. The SEC lists a wide range of people who can be liable, including corporate officers, directors and employees, professional advisers such as lawyers, bankers and brokers, government employees, and friends, family and business associates who receive tips. This is why the textbook contrast matters. Someone who genuinely overhears strangers discussing a deal on a train is in a different position from the company's lawyer, because they owe nobody a duty of confidence, even though both possess the same material nonpublic information. That contrast is narrower in practice than it sounds, because two further doctrines close most of the obvious gaps. ## Tipping, and the misappropriation theory **Tipping** extends liability outward. Passing material nonpublic information to someone else can be a violation, and the recipient who trades on it, the tippee, can be liable too. Handing the information to a relative does not launder it. **Misappropriation** extends liability sideways. It covers taking confidential information from your own employer or another relationship of trust and using it to trade, even where you owe no duty to the company whose shares are involved. A lawyer trading on what a client told them is the standard example: the duty breached is to the client, not to the issuer. Between them, these cover most of the arrangements people assume are clever. ## Why the trades are visible at all Corporate insiders are required to report their transactions to the SEC, and those filings are public. That reporting regime is the reason financial media can publish stories about executives selling shares within days of it happening. Insiders also commonly trade through pre-arranged plans under Rule 10b5-1, which are set up in advance, at a time when the person does not hold inside information, and then execute on a schedule regardless of what the insider learns later. The purpose is precisely to separate the decision to sell from any knowledge acquired afterwards. Those plans carry specific timing and disclosure conditions which we have not verified against a primary source for this piece, so check the current requirements before relying on them. The practical reading tip: a headline reporting that an executive sold shares tells you very little on its own. Whether the sale was scheduled months earlier under a plan, and what the filing actually says, is the information that matters. ## Why the SEC treats it as a priority The agency's stated rationale is that insider trading "undermines investor confidence in the fairness and integrity of the securities markets." That is worth taking seriously as an economic argument rather than a moral one. Public markets work because dispersed investors are willing to trade with strangers. If those investors believe the person on the other side systematically knows things they cannot know, they demand a wider spread or withdraw. The cost of insider trading is not mainly the profit taken by the insider; it is the liquidity and price efficiency lost by everyone else. ## What this means when you read the news Three things follow. An insider selling stock is not evidence of wrongdoing, and usually is not. The legal question in any given case is rarely whether the information was material and nonpublic, which is often obvious. It is whether a duty was breached and whether the chain from source to trader can be proved. And the visibility of insider transactions is a feature of the disclosure system working, not a sign that something was caught.