How the SEC’s Antifraud Rule Works, Why It Reaches Every Security and Every Person, and What the Exam Tests

Rule 10b-5 is the SEC’s main antifraud rule. It makes it unlawful for any person, in connection with the purchase or sale of any security, to use a scheme to defraud, to make an untrue statement of a material fact or leave out a material fact that makes what was said misleading, or to engage in any practice that operates as a fraud on anyone.

The SEC adopted the rule in 1942 under Section 10(b) of the Securities Exchange Act of 1934. It applies to every security, whether registered or exempt, publicly traded or privately sold, and to every person, not just brokers and advisers.

This guide covers what the rule says, who it applies to, how it underpins insider trading law, the elements of a 10b-5 claim, the penalties, worked examples, the exam traps and five practice questions with explanations. Preparing for your exam? Watch FRC’s Series 65 playlist on YouTube, with exam traps called out in every topic.

Why the Rule Exists

The Securities Act of 1933 deals mainly with the sale of new securities, and its antifraud provisions focus on offers and sales. In the early 1940s, the SEC found it had no clear power to act against fraud by buyers, such as an insider who bought shares from existing shareholders while hiding good news about the company.

Rule 10b-5 closed that gap. Drafted quickly in 1942, it reaches fraud by buyers as well as sellers, in any security, through any means of interstate commerce.

The rule has since become the foundation of US securities fraud law. Most insider trading cases, most private securities class actions and many SEC enforcement actions rely on it.

Where This Topic Appears on the Exams

Rule 10b-5 appears in the laws section of the Series 65, the SIE and the Series 7. Questions usually test its scope, its link to insider trading, and the principle that no security or transaction is exempt from antifraud rules.

FRC’s Series 65 Exam Preparation course covers the federal securities laws and the antifraud provisions of the Uniform Securities Act, and the exam requires no sponsor. The SIE Examination Preparation course introduces the Securities Exchange Act and insider trading, and the Series 7 Exam Preparation course tests them in more depth for registered representatives.

Every FRC course can be spread across interest-free monthly payments, so cost is no reason to delay. Antifraud questions turn up on every one of these exams, so the time you spend here pays off more than once.

What the Rule Says

Rule 10b-5 has three parts. Part (a) prohibits employing any device, scheme or artifice to defraud.

Part (b) prohibits making any untrue statement of a material fact, or omitting a material fact needed to make the statements made, in light of the circumstances, not misleading. Part (c) prohibits engaging in any act, practice or course of business that operates as a fraud or deceit on any person.

All three apply only “in connection with the purchase or sale of any security,” and only where the person uses interstate commerce, the mail or a national securities exchange. In practice, almost every securities transaction meets that jurisdictional test.

Who and What the Rule Covers

The rule applies to “any person,” which includes individuals and firms of every kind. Company insiders, brokers, advisers, accountants, lawyers and ordinary investors are all covered.

It also applies to “any security.” Exempt securities, such as municipal bonds and government securities, and exempt transactions, such as private placements, are excused from registration but never from Rule 10b-5.

That is one of the most heavily tested points on the exams. An answer suggesting that an exempt security is outside the antifraud rules is always wrong.

What Makes a Fact Material

A fact is material if there is a substantial likelihood that a reasonable investor would consider it important in deciding whether to buy, sell or hold a security. The Supreme Court adopted this test in Basic v. Levinson in 1988.

Merger negotiations, unannounced earnings results, a major lawsuit and the loss of a key customer are typical examples. Vague optimism, often called puffery, such as describing a company as “a great business,” is usually not material.

The trap is assuming only false statements breach the rule. A half-truth that leaves out a material fact, and so creates a misleading impression, breaches part (b) just as an outright lie does.

The Elements of a Private 10b-5 Claim

Although the rule does not say so, courts have long allowed private investors to sue under it. A private plaintiff must generally prove six things.

The first is a material misrepresentation or omission. The second is scienter, meaning intent to deceive or at least recklessness, as the Supreme Court required in Ernst & Ernst v. Hochfelder in 1976, and the third is a connection with the purchase or sale of a security.

The fourth is reliance, the fifth is economic loss and the sixth is loss causation, meaning the fraud caused the loss. Only actual buyers or sellers of the security can sue, a limit the Supreme Court set in Blue Chip Stamps v. Manor Drug Stores in 1975.

Rule 10b-5 and Insider Trading

There is no statute that defines insider trading in a single sentence. Most insider trading law has been built by the courts on Rule 10b-5.

Under the classical theory, an insider who trades on material, non-public information about their own company breaches a duty to the company’s shareholders. Under the misappropriation theory, upheld in United States v. O’Hagan in 1997, an outsider who trades on confidential information taken in breach of a duty to its source, such as a lawyer using a client’s merger plans, also violates the rule.

Tippers and tippees can be liable too. Under Dirks v. SEC in 1983, a tippee is liable when the insider breached a duty by sharing the information for a personal benefit and the tippee knew or should have known of the breach.

Rules 10b5-1 and 10b5-2

Rule 10b5-1 defines trading “on the basis of” material, non-public information as trading while aware of it. It also provides an affirmative defense for trades made under a written trading plan adopted before the person became aware of the information.

Since 2023, those plans carry a cooling-off period. Directors and officers must generally wait at least 90 days, and up to 120 days, before trading under a new plan, while most other people must wait 30 days.

Rule 10b5-2 sets out when a family or personal relationship creates a duty of trust and confidence for misappropriation purposes. Sharing confidences between spouses, parents and children, or siblings can create that duty.

Front-Running Is Not the Same as Insider Trading

Front-running involves trading ahead of a known client order to profit from the price move it will cause. Insider trading involves trading on material, non-public information about the issuer itself.

Both can breach antifraud rules, but the information is different. FRC’s guide to what front-running is explains the order-flow side in full.

On the exam, ask what the person knew. Knowledge of a company event points to insider trading, while knowledge of a pending order points to front-running.

Rule 10b-5 Compared With the 1933 Act’s Antifraud Provision

The Securities Act of 1933 has its own antifraud provision, Section 17(a), which covers fraud in the offer or sale of securities. Unlike Rule 10b-5, it does not reach fraud by buyers, and courts have generally held that it gives private investors no right to sue.

Rule 10b-5 is broader, because it covers both sides of a transaction and supports private lawsuits. That is why most securities fraud cases, public and private, are brought under Rule 10b-5.

Penalties for Violating Rule 10b-5

The SEC can bring civil actions seeking injunctions, disgorgement of profits and civil penalties. In insider trading cases, the civil penalty can be up to three times the profit gained or loss avoided, on top of disgorgement.

Willful violations of the Securities Exchange Act can also be prosecuted criminally by the Department of Justice. Individuals face up to 20 years in prison and fines of up to $5 million, and firms face fines of up to $25 million.

Private plaintiffs must generally sue within two years after discovering the violation and within five years after it happened. Professionals found liable can also face industry bars from FINRA, the SEC or state regulators.

Worked Example: An Insider Trading Case

A company director learns in confidence that her company is about to be acquired at a premium. Before the news is announced, she buys 10,000 shares at $20.

When the deal is announced, the shares rise to $28, giving her a profit of $8 per share, or $80,000. She has traded on material, non-public information in breach of her duty to shareholders, which violates Rule 10b-5 under the classical theory.

The SEC could seek disgorgement of the $80,000 and a civil penalty of up to three times that amount, or $240,000. That is up to $320,000 in total, before any criminal case or industry bar.

Worked Example: A Misleading Omission

A company’s chief executive tells investors that “sales of our main product remain strong.” He knows, but does not say, that the company’s largest customer, responsible for 40% of those sales, has just cancelled its contract.

The statement is technically true for the moment, but it leaves out a material fact that makes it misleading. A reasonable investor would consider the loss of the largest customer important.

That is a classic part (b) violation. Investors who bought shares relying on the statement, and lost money when the cancellation became public, may have a 10b-5 claim.

How Rule 10b-5 Applies to Advisers and Representatives

An investment adviser representative who misstates a product’s risks, hides fees or recommends a security while concealing a personal interest in it can violate Rule 10b-5. Advisers are also subject to the antifraud provision of the Investment Advisers Act, Section 206.

At state level, the Uniform Securities Act contains antifraud provisions modeled closely on Rule 10b-5. That is why exam questions on state law often use the same language about untrue statements and omissions of material fact.

FRC’s guides to FINRA Rule 2010 vs Rule 2020 and what the Investment Advisers Act of 1940 actually requires in practice cover the FINRA and adviser rules that sit alongside Rule 10b-5.

Client Scenario: Overheard Information

An investment adviser representative is at a family dinner when her brother-in-law, a senior lawyer, mentions that a client of his firm is about to announce a takeover. He asks her to keep it quiet.

If she buys shares in the target company for herself or her clients, she could be liable under the misappropriation theory, because family relationships like this one can create a duty of trust and confidence under Rule 10b5-2. Her firm’s code of ethics would also prohibit the trade.

The right course is to do nothing with the information and, if in doubt, speak to her compliance department. Protecting confidential information is part of the integrity employers look for in every adviser.

The Exam Traps

The first trap is assuming exempt securities are outside Rule 10b-5. No security and no transaction is exempt from antifraud rules.

The second trap is assuming only false statements breach the rule. Omitting a material fact that makes a statement misleading is just as much a violation.

The third trap is confusing insider trading with front-running. The fourth is assuming Rule 10b-5 comes from the Securities Act of 1933, when it was adopted under Section 10(b) of the Securities Exchange Act of 1934.

For more traps like these, see FRC’s guide to Series 65 exam traps and common mistakes. The Series 65 ethics questions guide covers the rest of the laws section in depth.

A Memory Aid

Remember “10b-5 lives in the ‘34 Act.” The rule number points to Section 10(b) of the Securities Exchange Act of 1934.

For the three parts, remember “scheme, statement, practice”: no scheme to defraud, no untrue or misleading statement, no fraudulent practice.

Practice Questions

Question one: under which law was Rule 10b-5 adopted? The Securities Exchange Act of 1934, under Section 10(b).

Question two: does Rule 10b-5 apply to the sale of a municipal bond, which is an exempt security? Yes, exempt securities are exempt from registration, not from antifraud rules.

Question three: a director buys 5,000 shares at $30 on inside information and sells at $36. What is the maximum civil penalty the SEC could seek, on top of disgorgement? $90,000, which is three times the $30,000 profit.

Question four: can a statement that is technically true violate Rule 10b-5? Yes, if it omits a material fact needed to make it not misleading.

Question five: who can bring a private lawsuit under Rule 10b-5? Only actual buyers or sellers of the security who meet the other elements of the claim.

Related Questions

Rule 10b-5 connects closely to the other federal securities laws on the exam. FRC’s guide to the Securities Act of 1933 covers the registration law that came first.

Get Exam-Ready

Antifraud questions are among the most dependable marks in the laws section once the scope of Rule 10b-5 is clear. The FRC Series 65 playlist linked at the top of this guide covers every exam section, with the traps to look out for in each one.

The FRC dictionary is more than a dictionary. It is a library of explainer videos, written explanations and on-page quizzes covering the FINRA and SEC rules you are tested on, so you can open any term and go deeper whenever a question catches you out.

Study With FRC

FRC’s programs and memberships are open to everyone. Whether you are preparing for the Series 65, the SIE, the Series 7 or all three, structured exam preparation turns topics like Rule 10b-5 into marks you can rely on.

FRC’s Professional Membership adds verified progress and a Digital Profile, so when you apply for roles, employers can see your exam progress and the knowledge you are building, not just read about it on a resume.

Your Next Step

Rule 10b-5 is the SEC’s main antifraud rule, adopted under the Securities Exchange Act of 1934. It prohibits fraudulent schemes, material misstatements and omissions, and fraudulent practices in connection with any securities transaction, by any person.

Remember “10b-5 lives in the ‘34 Act” and “scheme, statement, practice,” and you will be ready for every version of this question the exam can ask.