Wall Street hasn’t been too kind to Twitter lately, but someone sure likes the idea of Biz Stone coming back to keep an eye on things. Twitter Inc. shares jumped more than 2.5% today after Stone, a cofounder of the service, said in a Medium post that he’s coming back in a new role to focus on company culture. “There’s something about the personality of a company that comes from the folks who start it,” Stone wrote in a post that was apparently too long to fit in a tweet. Stone said he decided to come back to the company after being invited by CEO Jack Dorsey. Twitter shares were trading at $19.55 in midday, a high not seen since December 2016. Read Stone’s full post here.