Henry Kravis, co-chairman, co-chief executive officer and co-founder of KKR & Co., arrives for a session of the Allen & Co. Media and Technology Conference in Sun Valley, Idaho, July 6, 2016.

Shares of private equity giant KKR jumped on news Thursday morning that activist investing firm ValueAct has taken out a significant stake.

KKR's stock rose more than 6 percent after ValueAct principal Mason Morfit announced a stake of about 5 percent through derivatives.