TINA WYSKCommercial Litigation Attorney

Securities & Investment Disputes

Federal Securities Fraud: Rule 10b-5 Basics for Investors and Companies

Published November 7, 20265 min readSources checked November 6, 2026

Draft for attorney review

Short answer

Rule 10b-5 makes it unlawful to make an untrue statement of a material fact, omit a fact needed to keep statements from being misleading, or use any scheme to defraud in connection with the purchase or sale of any security. A private investor suing under it must prove a material misstatement or omission, scienter (knowledge or recklessness), a connection to a securities transaction, reliance, economic loss, and loss causation. The Private Securities Litigation Reform Act adds strict pleading rules and a discovery stay. The claim must be filed within two years of discovery and five years of the violation, in federal court.

Dallas Skyline with Arts District

What Rule 10b-5 prohibits

Rule 10b-5, adopted by the SEC under section 10(b) of the Securities Exchange Act of 1934, makes it unlawful for any person, directly or indirectly, in connection with the purchase or sale of any security, to employ any device, scheme or artifice to defraud; to make any untrue statement of a material fact or omit a material fact necessary to make the statements made not misleading; or to engage in any act, practice or course of business that operates as a fraud or deceit. It reaches any security, listed or not, so a founder's pitch for shares in a Dallas start-up is covered as fully as a public company's earnings release.

The rule itself says nothing about private lawsuits. Courts recognized an implied private right of action decades ago, and Congress later regulated it through the Private Securities Litigation Reform Act of 1995 (PSLRA) and set its deadline in 28 U.S.C. § 1658(b).

The six elements a private plaintiff must prove

  1. A material misrepresentation or omission. A false statement of fact, or silence where there was a duty to speak, that a reasonable investor would consider important. Puffery and opinions are generally not actionable unless the speaker did not hold the opinion.
  2. Scienter. An intent to deceive, manipulate or defraud. Courts in the Fifth Circuit, which includes Texas, accept severe recklessness. Negligence is not enough, which is the main difference from the Texas Securities Act.
  3. In connection with the purchase or sale of a security. The plaintiff must have bought or sold; a holder who merely kept shares in reliance on a lie has no 10b-5 claim.
  4. Reliance. The plaintiff acted on the misstatement. In public-market cases reliance can be presumed from an efficient market; in private deals it is proved directly.
  5. Economic loss. Money actually lost.
  6. Loss causation. The misstatement, not something else, caused the loss. Under 15 U.S.C. § 78u-4(b)(4) the plaintiff carries that burden.

What the PSLRA requires in the complaint

The PSLRA, 15 U.S.C. § 78u-4(b), raised the pleading bar in three ways. The complaint must specify each statement alleged to be misleading and the reasons it is misleading, and if an allegation is made on information and belief, state with particularity all facts on which the belief is formed. For each act or omission, it must state with particularity facts giving rise to a strong inference that the defendant acted with the required state of mind. And the court must dismiss on motion if either requirement is not met. In Tellabs, Inc. v. Makor Issues & Rights, Ltd. (2007), the Supreme Court held that the inference of scienter must be cogent and at least as compelling as any opposing inference a court can draw from the facts alleged.

Federal Rule of Civil Procedure 9(b) separately requires fraud to be pleaded with particularity. In practice a 10b-5 complaint identifies who said what, when, to whom, why it was false when said, and the facts showing the speaker knew or recklessly disregarded that falsity.

The discovery stay

Under 15 U.S.C. § 78u-4(b)(3)(B), all discovery is stayed while a motion to dismiss is pending unless the court finds particularized discovery necessary to preserve evidence or prevent undue prejudice. The effect is that a plaintiff must plead the case from public information, documents already in hand, confidential witnesses and the investor's own records, without the benefit of the defendant's files. For a defendant company, the stay means that a well-founded motion to dismiss can end the case before any email is produced. This is one reason the same facts are often pleaded first under Texas law in state court, where no such stay exists.

Example

Suppose a Dallas software company raises $4 million from twenty investors on a deck stating that a national retailer has "signed a three-year contract" worth $2 million a year. The retailer had signed a non-binding letter of intent and walked away two months before the deck went out; internal emails show the founders knew. The company fails eighteen months later. The investors have a Rule 10b-5 claim: a false statement of fact, scienter shown by the emails, a purchase of stock in reliance, a loss, and loss causation if they can show the company's collapse flowed from the missing contract rather than from, say, a later market shift. Pleaded with the emails, the claim should survive a motion to dismiss; pleaded only on the fact that the contract never materialized, it probably does not.

Deadlines

Under 28 U.S.C. § 1658(b), a private securities fraud claim must be brought within the earlier of two years after the discovery of the facts constituting the violation or five years after the violation. The two-year period runs from when a reasonably diligent plaintiff would have discovered the facts, including facts showing scienter, so it is often disputed. The five-year period is a statute of repose that courts in the Fifth Circuit and elsewhere treat as absolute. These periods differ from the Texas Securities Act's three years from discovery and five from the sale; the differences are compared in the deadlines guide.

Who can be sued

The primary violator is the person who made the statement or carried out the scheme. Section 20(a) of the Exchange Act, 15 U.S.C. § 78t(a), adds every person who directly or indirectly controls a primary violator, jointly and severally, unless the controlling person acted in good faith and did not directly or indirectly induce the violation; officers, directors and parent companies are the usual targets. Private plaintiffs cannot sue aiders and abettors under federal law: 15 U.S.C. § 78t(e) reserves that claim to the SEC. Texas law is broader on that point, as explained in the control-person and aider guide.

For companies accused

The federal claim gives a defendant tools the Texas claim does not: the particularity requirements, the strong-inference standard, the discovery stay, the loss-causation burden and the five-year repose. The early work is to test the complaint against each element, notify the directors-and-officers insurer, impose a litigation hold, and decide whether the Texas claims that usually accompany the federal one change the calculus. A company sued by its own investors should read the guide to defending an investor lawsuit. Tina Wysk represents investors and companies in securities fraud litigation in the federal courts in Dallas and in Texas state courts; see securities and investment disputes.

Questions on this topic

Does Rule 10b-5 apply to private companies and private deals?

Yes. Rule 10b-5 applies to any untrue statement or scheme in connection with the purchase or sale of any security, and the federal definition of security includes stock, notes and investment contracts in private companies. A founder's pitch, a private placement memorandum or a buyout negotiation can all give rise to a claim. What changes in a private deal is that reliance must be proved directly rather than presumed from an efficient market.

What is scienter and how do investors prove it?

Scienter is the intent to deceive, manipulate or defraud; courts in the Fifth Circuit also accept severe recklessness. Investors prove it with facts showing the speaker knew the statement was false or had access to contrary information: internal emails, prior drafts, contemporaneous reports, insider sales, or admissions. Under the PSLRA those facts must be pleaded with particularity and must create a strong inference of scienter before discovery opens.

What is loss causation?

Loss causation is the requirement, codified at 15 U.S.C. § 78u-4(b)(4), that the plaintiff prove the misstatement caused the economic loss. It is not enough that the price was inflated when you bought; you must show that the truth emerged and the loss followed, or that the hidden risk materialized. Market-wide declines, unrelated business failures and later events are the defendant's usual answers.

How long do I have to file a Rule 10b-5 claim?

Under 28 U.S.C. § 1658(b), the earlier of two years after discovery of the facts constituting the violation or five years after the violation. Discovery means when a reasonably diligent investor would have found the facts, including those showing scienter, so an early warning sign can start the clock. The five-year limit is a statute of repose that is not extended by concealment or tolling arguments.

Can I sue the company's lawyers, accountants or bankers under Rule 10b-5?

Only if they themselves made a false statement or carried out a deceptive act; there is no private claim for aiding and abetting under federal law, which 15 U.S.C. § 78t(e) reserves to the SEC. Texas law is different: Texas Government Code section 4008.055 makes a person who materially aided a sale liable if it acted with intent to deceive or reckless disregard, which is why professional-defendant cases are often pleaded under the Texas Securities Act.

Next step

Discuss an investment dispute

Tina Wysk handles securities & investments for businesses and individuals in Dallas state and federal courts. A short conversation is usually enough to see where you stand.

Sources

  1. 17 C.F.R. § 240.10b-5 (the prohibition on schemes, untrue statements and omissions in connection with the purchase or sale of any security)
  2. 15 U.S.C. § 78u-4(b) (PSLRA) (particularity, strong inference of scienter, mandatory dismissal, discovery stay, plaintiff's burden on loss causation)
  3. Tellabs, Inc. v. Makor Issues & Rights, Ltd., 551 U.S. 308 (2007) (the strong-inference standard: cogent and at least as compelling as any opposing inference)
  4. 28 U.S.C. § 1658(b) (two years from discovery, five years from violation)
  5. 15 U.S.C. § 78t (Exchange Act § 20) (control-person liability with good-faith defense; aiding and abetting enforceable only by the SEC)
  6. Fed. R. Civ. P. 9(b) (fraud must be pleaded with particularity)

Legal sources last checked November 6, 2026. Statutes and rules change; the date matters.

Tina Wysk

About the author

Tina Wysk

Shareholder, Hallett & Perrin, P.C.. Tina represents businesses and individuals, as plaintiffs and defendants, in contract, partnership, fiduciary duty, fraud, construction, trade secret and investment disputes in Texas state and federal courts and in arbitration.

About Tina

This guide is general information about Texas and federal law for business owners, not legal advice about your situation. Statutes, rules and court decisions change, and small facts change outcomes. Reading it or contacting Tina Wysk through this site does not create an attorney-client relationship.

CallDiscuss Your Matter