Who is considered an insider of a company?

An insider of a company is defined as an individual who has access to or knowledge of material non-public information about the company. This includes executives, directors, and employees who are privy to sensitive information that could influence an investor's decision if it were made public. The concept of insider trading revolves around the prohibition of trading securities based on this non-public information, as it presents an unfair advantage.

In the context of the other options, simply purchasing shares of the company does not by itself confer insider status, as anyone can buy stock as long as they adhere to regulations. The suggestion that all employees are insiders overlooks the fact that not all employees have access to confidential information. Furthermore, individuals working at competitor companies are not insiders; they may have market knowledge but do not have the same level of access to specific, sensitive information about the company in question. Thus, the definition of an insider is specifically tied to having non-public information that could materially affect the company's stock price.