Activists win again with Yum. Which stock is next?

Keith Meister
Adam Jeffery | CNBC

Yum Brands shares rallied as much as 5 percent Tuesday on news that the company will spin off its China division. The decision gives a victory to activist investor Keith Meister of Corvex Management, who advocated for the move.

Activists have never been more active than they are today, and Yum's may be the first of a flurry of moves made by companies before the end of the year to satisfy these "barbarians at their gates."

The number of investors pursuing activism is surging in recent years. In 2015, 315 investors publicly targeted a company with an activist demand, up from 282 in 2014, according to the tracking firm Activist Insight.

Their success rate is also increasing with 62.5 percent of activist campaigns becoming at least partially successful in 2015, up from 59.9 percent last year, the firm says.

Companies listed below have notable activist investors involved, but have yet to embark on any significant corporate changes at the behest of the big investors.

This is where the next activist-friendly action could come from...