ELI5: Explain Like I'm 5

Activist shareholder

An activist shareholder is someone who owns shares in a company and wants to make changes in that company. They do this by speaking up at shareholder meetings, making suggestions to management, and sometimes even voting for directors on the board of the company. They usually are trying to make the company run better in some way: make more money, be more efficient, or do something else that they think will improve the company.