Leaving the nest

TWITTER'S share price is up nearly 2% on news that its chief executive, Dick Costolo, will step down on July 1st. The microblogging site’s co-founder and chairman, Jack Dorsey, will replace him temporarily. Although the number of monthly active users topped 300m in the first quarter, growth has been slowing; revenue of $436m, though up 74% year-on-year, was less than expected. Twitter, a relative minnow in today's tech sea, as the above interactive shows, looks an enticing takeover target.