In the context of securities, an “insider” is an individual with who has nonpublic information about a corporation due to their position or intimate association with the corporation. Insiders include the officers, directors, and employees of a corporation, but also those working in a fiduciary capacity for the corporation, such as attorneys and accountants. The use of such nonpublic information when trading stocks or other securities may constitute insider trading, which is a crime under the Securities Exchange Act.
[Last updated in June of 2020 by the Wex Definitions Team]