Activist Hedge Fund
Historically, most hedge funds have avoided publicity. Activist hedge funds, however, will try to increase the value of their investments by actively calling for change at a company.
As an example, an activist fund might slowly buy shares in a publicly traded company that has a great product but terrible marketing. Once the fund has a significant position, they would publicly call for management at the company to make changes to their sales strategy. The hedge fund will make money if they can convince the company to change, and this change leads to an increase in the stock price. Sometimes, but not always, the fund may try to influence the company by getting a board seat, or by calling for a shareholder vote.
When this strategy works, it can lead to significant positive returns. At the same time, activist hedge funds often have very concentrated, illiquid portfolios, and this strategy is often associated by returns with significant excess kurtosis.