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

The Supreme Court ruled that a company's failure to disclose information required by SEC regulations does not automatically create liability for securities fraud under Rule 10b-5(b) unless that omission makes an actual affirmative statement misleading. The unanimous decision clarified that "pure omissions"—simply failing to speak when required—are not actionable under this specific anti-fraud rule, which targets half-truths rather than silence.