- a person inside a given place or group
- a person having or likely to have secret or confidential information
- An accepted member of a group.
- One who has special knowledge or access to confidential information.
inside + -er
insider - Investment & Finance Definition
Someone who knows about important information before it becomes public. An insider may be an employee, a company director, someone who works closely with the company, or someone who owns at least 10 percent of the company. Insiders, including their friends and family members, are prohibited from trading on inside information that has not yet been announced to the public.