A pre-established program, set up under the guidelines in SEC Rule 10b5-1, to sell your company's stock. Its purpose is to avoid insider-trading violations even when you possess and are aware of confidential, important information that may affect the company's stock price. The rule creates an "affirmative defense" that can shield you from insider-trading liability under SEC Rule 10b-5 for the actual stock transaction. However, you must follow certain conditions to use this rule, and expert legal advice is necessary before relying on it. For more details, see the section SEC Law: Rule 10b5-1 Trading Plans.