The reasons you give as reasons why a billionaire can go bankrupt due to economic problems are quite reasonable. However, another reason that can be the main benchmark for a billionaire to go bankrupt is because he has not developed himself well so he no longer has good innovation to be able to develop his company. I think this could be the exact reason why a billionaire goes bankrupt. Because what I know is that billionaires have a lot of innovation, no matter what economic conditions are happening in the world, they can still survive and even continue to make profits as usual. So in essence, the world economic situation is not good, I don't think it can make a billionaire bankrupt. Because I am sure that a billionaire will not be defeated by the global economic situation. In fact, they can take advantage of the bad economic situation into an advantage. Because if we think logically, people who have become billionaires means that person has really great thinking. Therefore, it will not be easy to take him down.