A perspective that defines the act of stealing confidential information from an employer and then trading securities based on the misappropriated insider knowledge. In the United States, a person guilty according to the misappropriation theory will likely be convicted of insider trading. Taobiz explains Misappropriation Theory The misappropriation theory gained prominence in the Supreme Court's conviction of James H. O'Hagan. O'Hagan was an attorney who acted on insider information regarding a takeover bid for Pillsbury. The United States versus O'Hagan was a watershed case for the theory, defining its validity. This take on insider trading expands the traditional view of what constitutes guilt. Instead of looking only at people who trade their own companies' shares based on stolen information, the theory extends to those who use the knowledge to profit in any corporation.