Here's another activist hedge fund having a huge year

Barry Rosenstein, founder and managing partner of Jana Partners
Daniel Acker | Bloomberg | Getty Images

Activist hedge fund firm JANA Partners has been very, well, active.

On Sept. 5, JANA said in a Securities and Exchange Commission filing that its stake in energy company Oil States International had grown from 9.1 percent to 11.7 percent.

On Sept. 17, the hedge fund filed another government form, this time disclosing a 6.2 percent stake in supermarket chain Safeway (JANA said the company should cut stores in under-performing geographies; Safeway responded by ).

On Sept. 20, JANA said it had added to its investment in chemical company Ashland—up from 7.4 percent in April to 8.4 percent.