I posted this earlier in another thread but I'll post it here for those that missed it. Here's why I believe there's legs to this story.
I actively trade the stock market on a daily basis, about 2 days ago there was some insane and sustained volume on options on the Man Utd stock. Specifically call options (you buy contracts worth 100 shares each and you state a price you think the stock is going to and by which date, high risk, high reward, they expire worthless if it doesn't happen).
To put in perspective how much this is abnormal for the Man Utd stock, trading volume was up 3500% on the stock from your average day.
The call options are for the price to hit $14 within the next 31 days. There has been a large amount of money placed on this happening.
Fast forward two days later and Musk makes a joke about *buying Manchester United and Bloomberg (responsible for all serious market news and data) publish a story about Glazers looking to sell a stake.
There's one of two things at play here, Musk has taken part in some clear market manipulation (which he's been found guilty for a few times) and this is a planned joke on the market in general. When something like this happens it attracts day traders to jump in which creates more volume, it happens to a lot of random stocks, see GME, AMC and BBBY for examples.
OR
A stake in Manchester United is being offered around the wealthy in America and someone with that kind of inside information is having a punt the stock going up.
In my opinion is the latter of the two.