This is because rich people are big risk takers and make huge gambles, and know they can lose it all quickly. At least for people involved in business or finance.
they all have some money to begin with, its just play money to them.
The owner of walmart dad was a banker who loaned him the money for his start up.
Not everyones parents are bankers lol
Trump and Richard Branson had help from their parents, took risks and were in some respect lucky they werent exactly dealing with small change.
Most people dont have that luxury of being able to play the stockmarket, or make investments etc. The investments have to be huge to begin with. If you need money, most people have to apply for a loan from the bank and they have to convince them that its worth the risk, though rich people always have extra houses, land and stuff they can sell. And they know other rich people who could lend them money. Its not like they ever had to live hand to mouth.