Macquarie Infrastructure Corp. v. Moab Partners, L. P.

The Supreme Court ruled unanimously that a company cannot be sued for securities fraud just because it failed to disclose information required by SEC regulations. The Court held that under Rule 10b-5(b), a 'pure omission'—simply staying silent when required to speak—is not enough for a private lawsuit unless that silence makes other specific statements misleading. Because Macquarie Infrastructure Corp. did not make an affirmative statement that was rendered false by its silence, the earlier ruling against them was vacated (canceled).

This decision makes it harder for shareholders to sue companies for failing to follow SEC disclosure rules unless they can point to a specific statement that became a 'half-truth.' Investors who lose money because a company kept secrets may now have fewer legal options to recover their losses in private court cases. For example, a company that stays silent about a looming business risk might avoid fraud liability even if SEC rules technically required them to mention it.

The case centers on the balance between protecting investors from fraud and preventing a flood of lawsuits over technical regulatory failures. Historically, courts have debated whether the SEC's requirement for companies to disclose known trends or uncertainties automatically creates a right for individuals to sue if those disclosures are missing. This ruling clarifies that the primary anti-fraud rule used by investors is focused on active deception rather than just failing to check every regulatory box.

The Court ruled 9-0 to vacate the lower court's decision, with Justice Sonia Sotomayor writing the unanimous opinion for all nine justices.

“Pure omissions are not actionable under Rule 10b–5(b). The plain text of Rule 10b-5(b) bars only half-truths, not pure omissions.”

Companies cannot be sued for securities fraud for 'pure omissions' of required information unless their silence makes an actual statement misleading.

The case will return to the lower courts to determine if any of Macquarie's specific statements were actually misleading half-truths. Investors and legal experts will now watch how lower courts apply this 'half-truth' standard to other pending fraud cases. While private lawsuits are now more limited, the SEC still has the power to punish companies that fail to follow its disclosure rules.

Moab Partners sued Macquarie for not disclosing how new environmental regulations would impact their fuel storage business. They argued this silence was a form of fraud.

Investors may find it more difficult to win lawsuits when companies hide bad news. They must now prove the company made a specific statement that was misleading.

The Court clarified Rule 10b-5(b), stating it only prohibits omitting facts necessary to make 'statements made' not misleading. It does not cover 'pure omissions' or total silence.

The case is vacated and remanded (sent back) to the lower court. Judges there must decide if Macquarie's actions involved any misleading half-truths.

This ruling continues a trend of the Court narrowing the scope of private fraud lawsuits. It emphasizes that Congress and the SEC must be explicit when creating liability.