Where will Musk get the cash to pay for Twitter?

The other possibility: Musk is even richer than calculated by the Bloomberg Billionaires Index.

Musk’s cash estimate is based on filings related to publicly traded shares and news reports, but much of the information on his private finances is limited. If his portfolio of investments has outperformed the market, for instance, Musk could be wealthier than the Bloomberg estimate and he might not need new sources of funding to cover the $21 billion.

Musk said in July he owned Bitcoin, Ether and Dogecoin. While it’s not clear how much he holds or for how long he’s owned them, the first two cryptocurrencies have gained about 720% and 2,600%, respectively, since March 2020, a much steeper rally than the roughly 90% advance in the S&P 500 Index. Dogecoin, meanwhile, surged almost 30% on Monday after Musk agreed to buy Twitter.