It seems Jack Dorsey’s abrupt departure as CEO of Twitter was welcome news to the company’s long-suffering shareholders—until it wasn’t. A 10% uplift in Twitter shares that was triggered by the initial headline evaporated shortly after Twitter identified his successor as Chief Technology Officer Parag Agrawal. Talk about going from the devil you know to the one you don’t! Twitter shares ended the day down 2.7%.

That's not surprising. Until now Agrawal has overseen Twitter’s technical strategy—he helped boost Twitter’s use of cloud providers, for instance. That makes him a curious choice to be CEO, given the political and investor pressures Twitter’s leader must contend with regularly. Then again, Dorsey was doing the job part time while he also ran Square, so how much worse can Agrawal be?