Dick Costolo cycled through lots of senior executives during his five-year run at Twitter. So it made sense that eventually he would have to leave, too. And when he did, Wall Street cheered, pushing the stock up as much as 7 percent.
But that was yesterday. Today, Twitter stock is back down again, right where it was before the company announced Costolo was out.

His replacement, Jack Dorsey, is only there on an interim basis. Maybe Twitter’s board can see what happens if it replaces itself.
This article originally appeared on Recode.net.
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