Corporate Raider

What Does Corporate Raider Mean?
An investor who buys a large number of shares in a corporation whose assets appear to be undervalued. The large share purchase would give the corporate raider significant voting rights, which could then be used to push changes in the company’s leadership and management. This would increase share value and thus generate a massive return for the raider.

Investopedia explains Corporate Raider
Companies have used a variety of strategies to thwart the efforts of corporate raiders. These include shareholders’ rights plans (poison pills), super-majority voting, staggered boards of directors, buybacks of shares from the raider at a premium price (greenmail), dramatic increases of the amount of debt on the company’s balance sheet and strategic mergers with a "white knight."

Famous corporate raider Carl Icahn used tactics such as taking a company private, compelling a spin-off, calling for an entirely new board of directors or calling for a divestiture of assets to make a fortune with his hostile takeovers.