This is just pointless lazy "news" and should be ignored. Imo this is actually harmful reporting as it takes up attention that could go to other things.

You can make a variation of this story automatically every single day. "[Insert random billionaire who has his wealth concentrated in a single company (which probably are most)] loses/gains $X billion in a day" whenever the share price of a stock moves.

It might sound like a lot, but practically it's irrelevant as they still have more money that could ever be used and their influence over things like e.g. the company is only tied to their percentage of ownership.

Now if Mark Zuckerberg would lose or divest actual shares of Facebook that would be newsworthy, as it might change the level of control he has. But of course that isn't what happened.