Many people do not understand this. It is thought that a rich person who has 5 billion net worth, has them as cash, and the truth is that if he has them mostly in shares, and tried to sell them massively, it would cause a considerable drop in the share price, and he would have to pay taxes, so he would have much less. But well, having that wealth ensures him a high lifestyle, even if he is short of cash, as Elon likes to go, the banks welcome him with open arms and give him plenty of loans.