This week Elon Musk announced that he'd acquired a 9% stake in social media site Twitter, earning him not only a seat on the company's board, but also the title of the company's largest shareholder, with more than 4x the shares held by founder and ex-CEO Jack Dorsey.
The Elon effect
The news has sent shares in Twitter up more than 30%, with more than $13 billion worth of shares changing hands on Monday alone. That's more than double even the busiest days of trading from Twitter's 8-and-a-half years as a public company. It's way more than the $5bn that changed hands on Twitter's first day of trading after its IPO, it's more than was traded when Google was rumored to be looking at acquiring Twitter in 2016 and it's 4x what was traded when Donald Trump was banned from the platform last year.
A billionaire's playground
Musk's interest in Twitter is unlikely to be directly financial. With a net worth north of $200 billion, his stake in Twitter represents just over 1% of his wealth. But he uses the platform more than any other major public figure, promoting Tesla, SpaceX and - increasingly - his views on free speech and politics in between memes and jokes.
At its most serious, Elon's involvement might mean a substantive change in Twitter's moderation or free-speech policies... or he might have literally just spent ~$3bn to get an edit button.
