A Practice Note discussing strategies for defending against civil securities fraud cases brought by private plaintiffs under Section 10(b) of the Securities Exchange Act of 1934 and Securities and Exchange Commission Rule 10b-5 because the plaintiff failed to plead or prove the falsity and materiality element of their claim. This Note explains the requirements for pleading and proving materiality in a case based on misrepresentations or omissions, and provides practical guidance for challenging the plaintiff's claim at the motion to dismiss, class certification, and summary judgment stages.