His reassignment comes on the heels of two top Twitter executives— Jana Messerschmidt, the head of business development, and Nathan Hubbard, the head of media and commerce— announcing their departures at the end of May. It also follows a crippling exodus of four top Twitter execs roughly six months ago. As Twitter struggles to iron out its revenue model and grow its stagnant user base, this state of constant executive shuffling does not bode well for Dorsey. While internal conflicts and executive expulsions are nothing new for the decade-old company, Twitter's stock price has been nearly halved since the co-founder retook the top job. The lack of stable leadership in the product department—arguably the most important department within the company—will undoubtedly make it harder for Twitter to find its niche in an increasingly crowded social media market. Even Dorsey acknowledged that the leadership turnover is a problem and has contributed to the lack of user growth.