Gadfly

What Does Gadfly Mean?
A slang term for an investor who attends the annual shareholders meeting to criticize the corporation's executives. A gadfly addresses many issues for the shareholders, often grilling the management by asking difficult or embarrassing questions.

Investopedia explains Gadfly
Named after small insects that bite and annoy livestock, the gadfly looks to irritate a corporation's management until it acts on shareholder concerns. Questions regarding executive compensation or inconvenient annual meeting locations are often brought to light by a gadfly. A gadfly adds value for other shareholders by vocalizing their concerns and inciting action.