What Elon Musk's dance with Twitter really means

Tesla CEO Elon Musk's great Twitter turnabout _ in which he disclosed his massive stake in the social media company, got a seat on its board, publicly floated drastic changes and then turned down the board role _ all happened in a week.
But its aftermath could linger if the mercurial billionaire who now holds a roughly 9% stake in Twitter continues to push forward his ideas for reshaping the business of social media.

Twitter CEO Parag Agrawal said Musk's not joining was ``for the best'' but didn't give explicit reasons in a statement Monday. Agrawal also left some clues, noting that Musk had been awaiting a background check and suggesting that Twitter wanted him on the board _ rather than just as a major shareholder _ because as a fiduciary he'd be legally and ethically bound to act ``in the best interests of the company and all of our shareholders.''

Musk has been tweeting for a long time, but he began buying Twitter stock in earnest only a few months ago. He started on Jan. 31, when he bought a little more than 620,000 shares at $36.83 apiece. On nearly every single trading day from then through April 1, he bought hundreds of thousands or millions more of shares.

Musk seemed to be Twitter's biggest shareholder until investment giant Vanguard Group filed a report late last week showing it had supplanted him.
Vanguard controls 10.3% of the company through investments made by its suite of mutual funds and ETFs. Vanguard and other fund giants are often the biggest investors in any company, as money keeps pouring into their index funds from retirement savers and other investors. But these fund giants are typically much more hands-off as owners than activist investors, who can push for new management teams or big changes in strategy.