The principal private securities fraud claim requires a material misrepresentation or omission, scienter, a connection with the purchase or sale of a security, reliance, economic loss, and loss causation.

Materiality. A substantial likelihood that a reasonable investor would consider the fact important in deciding how to act, viewed against the total mix of available information.

Scienter. Intent to deceive, manipulate or defraud, satisfied in most circuits by recklessness amounting to an extreme departure from ordinary care. Heightened pleading requires facts giving rise to a strong inference, at least as compelling as any opposing innocent inference.

Reliance may be presumed where the claim rests on an omission, or through the fraud-on-the-market theory for securities trading in an efficient market — a presumption the defendant may rebut by showing the misstatement had no price impact.

Loss causation requires that the misstatement, rather than intervening market events, caused the loss. A corrective disclosure followed by a price decline is the standard proof, and disentangling it from confounding news is where damages experts contend.

Safe harbor for forward-looking statements accompanied by meaningful cautionary language, which requires the warnings to be specific rather than boilerplate and updated as risks materialize.