The best way to deal with activists is to get into and ahead of their thinking. In Agitators and Reformers: How to Respond to Activist Investors, Bain Partners Josh Hinkel, Henrik Poppe, Martin Toner and Chuck Whitten lay out seven categories that activist investors focus on.

"Most activists", they write, "still lead off with a demand for changes in corporate governance, such as new board members or a new CEO. A minority—those whom many companies view as agitators—have no publicly stated thesis beyond that. They just want to stir the pot, in hopes that somebody will address what they see as an undervalued stock."