Activists Step Up to Revamp C Suite at Microsoft to J.C. Penney

Activist investors from Carl Icahn to Daniel Loeb and Bill Ackman are ratcheting up their campaigns, increasingly targeting America’s biggest companies and seeking the ouster of chief executive officers.

Taking executive scalps has paid off for shareholders at companies such as Yahoo! Inc., Chesapeake Energy Corp. and Nutrisystem Inc., according to data compiled by Bloomberg. There have been flops, too, including Ackman’s CEO replacement efforts at J.C. Penney Co. Its stock has fallen 62 percent.