The Ranks of Global Billionaires: Not All Billionaires Are Made Equal

Just because he has Amazon stocks of that value doesn't mean he can turn all of that into cash. Economics explained has a great video on the various types of billionaires [1], which uses Jeff directly as an example of the lowest class of billionaire. [1]: this video

fyi youtube video of why these simplistic comparisons of "net worth" based on shares-times-stockprice is meaningless... - The Ranks of Global Billionaires: Not All Billionaires Are Made Equal : this video E.g. Theranos owner Elizabeth Holmes once had a "net worth" of 4.5 billion (as calculated by Forbes Magazine[1] for attention-grabbing headlines) ... but that doesn't really mean she was actually 2x richer than Dropbox's Drew Houston who's worth ~2 billion. That said, Elon Musk is a bonafide billionaire but the comparison to Buffett via a volatile Tesla stock price is meaningless. [1] link

Here's a fun video which discusses the phenomenon you're describing. Its a bit click-baity but does provide an overall summary pretty nicely. Economics Explained - The Ranks of Global Billionaires: Not All Billionaires Are Made Equal: this video It even covers the oligarchy scenario :)

Economics Explained did a great video on the topic of how diversification is a big problem for some billionaires: this video