Who: Founded in 2002 by Christer Gardell, a management consultant-turned-hedge fund manager who has been dubbed a capitalist "butcher," and ex-investment banker Lars Förberg, who is based in Zurich.
What: The firm, backed by billionaire financier Carl Icahn, is the largest activist investor in Europe. It has positions in automaker Volvo, German conglomerate ThyssenKrupp, and British private security firm G4S.
AUM: $11.7 billion as of March 2016 (Source: Activist Insight)
Big Hit: Cevian urged British engineering company Cookson to spin off its performance materials unit at the end of 2012, which drove up investment value for the company's shareholders by more than 25%, according to Bloomberg.
Big Miss: Harlan Zimmerman, London-based senior partner at Cevian, told Business Insider that the firm has had two losses since its inception: a 20% loss in turning around Norwegian firm CTG and another "small loss" in insurance firm Munich Re.