The phrase "insider trading" appears regularly in financial news, almost always attached to a scandal or criminal prosecution. This creates a widespread misconception: that insider trading is inherently illegal. It is not. The vast majority of insider trading is entirely lawful, publicly reported, and happens thousands of times every week across US public markets.
What distinguishes legal insider trading from illegal insider trading is not who is trading, but what information they possess when they trade and whether they have a duty not to use it. Understanding this distinction requires looking at two different sections of US securities law that serve fundamentally different purposes.
This guide explains how the regulatory framework works — the legal obligations that apply to corporate insiders, the prohibitions that apply to anyone who trades on material non-public information, and the enforcement mechanisms the SEC uses to police the boundary between the two.
Legal Insider Trading: Section 16 of the Exchange Act
Corporate insiders — officers, directors, and shareholders who beneficially own more than 10% of a company's equity securities — are permitted to buy and sell their company's stock. Congress did not prohibit insider transactions when it passed the Securities Exchange Act of 1934. Instead, Section 16 of the Act created a transparency regime: insiders can trade, but they must disclose those trades to the public.
The Reporting Obligation
Under Section 16(a), insiders must report their transactions on SEC Form 4 within two business days of the trade. Before the Sarbanes-Oxley Act of 2002 accelerated the deadline, insiders had up to 40 days to disclose. The current two-day window means that when a CEO buys shares on Monday, the public filing typically appears on EDGAR by Wednesday.
These filings are available to anyone. They disclose the insider's name, their relationship to the company, the type of transaction (purchase, sale, option exercise, gift), the number of securities, the price, and the insider's resulting ownership position. The SEC's EDGAR database receives thousands of Form 4 filings each week.
The Short-Swing Profit Rule
Section 16(b) imposes an additional constraint. Any profit that an insider realises from a purchase and sale — or sale and purchase — of their company's securities within a six-month window must be disgorged to the company. This is a strict-liability provision: it does not matter whether the insider possessed material non-public information. If the timing of the transactions falls within the six-month window and a profit results, the company can recover that profit.
The short-swing rule was designed as a blunt prophylactic measure. Congress recognised in 1934 that it would be difficult to prove whether an insider possessed confidential information at the time of a trade. Rather than rely on intent-based enforcement, Section 16(b) simply removes the financial incentive for rapid round-trip trading by insiders.
What Makes It Legal
Section 16 creates transparency, not prohibition. An insider who files the required forms, complies with the short-swing rule, and does not trade while in possession of material non-public information is engaging in entirely lawful activity. Many insiders trade routinely — exercising stock options as part of compensation, selling shares for diversification, or purchasing additional shares. These are legitimate financial decisions that insiders are entitled to make.
Illegal Insider Trading: Section 10(b) and Rule 10b-5
Illegal insider trading is a different legal concept governed by different provisions of securities law. Section 10(b) of the Securities Exchange Act of 1934 is a broad anti-fraud provision that prohibits any person from using "any manipulative or deceptive device" in connection with the purchase or sale of securities. Rule 10b-5, adopted by the SEC in 1942, implements Section 10(b) by making it unlawful to engage in fraud, make material misstatements, or omit material facts in connection with securities transactions.
Unlike Section 16, which applies only to defined corporate insiders, Rule 10b-5 applies to anyone — an insider, a consultant, a government employee, a friend, or a taxi driver who overhears a conversation. The question is not who you are, but what you knew and whether you had a duty not to trade on it.
The Classical Theory
Under the classical theory of insider trading liability, corporate insiders owe a fiduciary duty to their company's shareholders. When an insider possesses material non-public information (MNPI) and trades the company's securities without disclosing that information, they breach their fiduciary duty. The insider must either disclose the information before trading or abstain from trading entirely — the "disclose or abstain" rule established by the SEC and affirmed by the courts.
This theory is straightforward in its application: a CFO who knows about an unannounced earnings shortfall and sells shares before the announcement has breached a fiduciary duty to the shareholders on the other side of that trade.
The Misappropriation Theory
The Supreme Court expanded the scope of insider trading liability in United States v. O'Hagan (1997). The misappropriation theory holds that a person commits securities fraud when they misappropriate confidential information from a source to whom they owe a duty of trust and confidence, and then trade securities based on that information.
Under this theory, the trader does not need to be a corporate insider. The duty that is breached is not owed to the company's shareholders, but to the source of the information. The Court's decision in O'Hagan involved a lawyer who traded in the securities of a company that was the target of an acquisition his law firm was representing — he owed a duty to his firm and its client, not to the target company's shareholders.
The misappropriation theory significantly expanded the universe of people who can be prosecuted for insider trading. It covers, for example, a banker who trades on information learned through their employer's advisory relationship, or an accountant who trades on information from an audit client.
Tipper-Tippee Liability
Insider trading liability extends beyond the person who possesses the MNPI. In Dirks v. SEC (1983), the Supreme Court established the framework for "tipper-tippee" liability. Under Dirks, a tipper who discloses MNPI in breach of a fiduciary duty is liable if they received a personal benefit from the disclosure. A tippee — the person who receives the tip — is liable if they knew or should have known that the tipper breached a duty in disclosing the information.
The "personal benefit" element has been the subject of extensive litigation. Courts have interpreted it broadly to include not only direct financial gain but also reputational benefit, gifts of information to friends and family, and reciprocal exchanges of information. The Second Circuit's decision in United States v. Newman (2014) briefly narrowed the standard by requiring a closer personal relationship between tipper and tippee, but the Supreme Court's subsequent decision in Salman v. United States (2016) clarified that a gift of MNPI to a trading relative or friend is sufficient to establish personal benefit.
What Counts as Material Non-Public Information
The concept of materiality is central to insider trading law. The standard comes from TSC Industries, Inc. v. Northway, Inc. (1976): information is material if there is a "substantial likelihood that a reasonable investor would consider it important" in making an investment decision. This is an objective test — it does not depend on what the individual trader thought.
Information is non-public if it has not been disseminated to the investing public through established channels. A company's internal earnings projections are non-public. Once the company issues an earnings release through a press release or SEC filing, that information becomes public — although the SEC has noted that the market needs adequate time to absorb the disclosure.
The combination of these two elements — material and non-public — defines the boundary. Trading on information that is material but already public is lawful. Trading on information that is non-public but immaterial is lawful. Trading on information that is both material and non-public is where liability attaches.
How the SEC Detects and Enforces Insider Trading Violations
The SEC's Division of Enforcement is responsible for investigating and prosecuting insider trading cases. The regulatory enforcement system operates through several mechanisms.
Market Surveillance
The SEC and self-regulatory organisations such as FINRA maintain surveillance systems that monitor trading activity across US markets. These systems are designed to identify anomalous trading patterns around corporate events — unusual volume, price movement, or options activity in the days or hours before a material announcement. When the surveillance systems flag anomalous activity, the SEC can issue subpoenas for trading records, phone records, and communications to investigate whether MNPI was involved.
Whistleblower Programme
The Dodd-Frank Act of 2010 established the SEC Whistleblower Programme, which provides financial incentives for individuals who report securities law violations. Whistleblowers who provide original information that leads to a successful enforcement action with sanctions exceeding $1 million are eligible for an award of 10% to 30% of the amount collected. The SEC has reported that the programme has become a significant source of enforcement leads.
Penalties
Penalties for insider trading violations can be both civil and criminal. On the civil side, the SEC can seek disgorgement of profits (or avoided losses), pre-judgement interest, and civil monetary penalties. The Insider Trading Sanctions Act of 1984 authorised the SEC to seek civil penalties of up to three times the profit gained or loss avoided — commonly referred to as "treble damages."
On the criminal side, the Insider Trading and Securities Fraud Enforcement Act of 1988 established criminal penalties for wilful violations. Individuals face up to 20 years in prison and fines of up to $5 million per violation. The Department of Justice prosecutes criminal insider trading cases, often in parallel with SEC civil actions.
The Grey Areas
The boundary between legal and illegal insider trading is not always clear. Several areas of the law remain contested or evolving.
The definition of material non-public information is inherently context-dependent. Whether a particular piece of information is "material" depends on the circumstances — the same fact pattern might be material for one company and immaterial for another. Whether information is "non-public" can also be ambiguous, particularly in cases involving selective disclosure or information that is technically available but not widely disseminated.
Social connections between company insiders and traders create persistent questions about tipping. The SEC has brought cases where MNPI was passed through chains of friends, golf partners, and professional acquaintances. Proving that a tippee knew or should have known the information was obtained in breach of a duty becomes more difficult as the chain grows longer.
The intersection of government and securities trading has received increased attention. In 2022, the SEC charged a former US congressman with insider trading based on information obtained through congressional briefings about the COVID-19 pandemic. The case illustrated the expanding scope of the misappropriation theory — duties of trust and confidence extend well beyond the corporate boardroom. Political intelligence firms, which gather information from government sources and sell it to institutional investors, operate in a space where the legal boundaries remain unsettled.
These grey areas are a feature of a principles-based enforcement regime. The law is deliberately broad to cover novel fact patterns, which means the precise boundary of liability is often established only through enforcement actions and court decisions.
How Akivus Uses Legal Insider Trading Data
Akivus tracks legal insider trading through the public record. Every piece of data in the Akivus platform comes from SEC filings submitted to EDGAR — primarily Form 4 filings that corporate insiders are required to file under Section 16 of the Exchange Act. This is the lawful, transparent side of the insider trading framework described above.
The Akivus significance scoring system evaluates the context of these publicly reported transactions. When a Form 4 filing appears on EDGAR, Akivus processes it through the Thesma API platform to add context: the insider's role, the size of the transaction relative to their holdings, the timing relative to other filings, and other publicly available factors. The goal is to help users navigate the volume of Form 4 filings — thousands are filed each week — by identifying which transactions have notable contextual characteristics.
Akivus has no connection to illegal insider trading. The platform does not attempt to detect, predict, or analyse unlawful trading activity. It processes public filings that insiders are legally required to submit. The distinction is fundamental to how the product works: Akivus is a tool for reading the public record more efficiently, not a surveillance or enforcement mechanism. For details on how the scoring methodology works, see the scoring methodology page.