9 > 12 > 15 Cath is an accountant with Discount Corporation. Efrem buys Discount stock and loses money on the investment. 18 recover from Cath under Section 10(b) of the Securities Exchange Act of 1934 and SEC Rule 10b-5, Efrem must prove only the purchase and sale of a security. fraud, reliance, materiality, and lack of knowledge about securities. fraud, reliance, materiality, and incompetence. fraud, reliance, materiality, causation, and scienter