SEC Rule 10b-5, codified at 17 CFR 240.10b-5, is one of the most important rules targeting securities fraud in the United States. It was promulgated by the U.S. Securities and Exchange Commission (SEC), pursuant to its authority granted under § 10(b) of the Securities Exchange Act of 1934.[1] The rule prohibits any act or omission resulting in fraud or deceit in connection with the purchase or sale of any security. The issue of insider trading is given further definition in SEC Rule 10b5-1.