Most of their money isn't liquid. At least half is usually tied to ownership of a single company. In some cases multiple companies. But they know the value of money. Your phone is the same phone they have, it doesn't get any better, same with their laptop, most of their clothes, and probably their car, unless they like attention. Gates probably parked elsewhere because he didn't have that much cash on him. None of these guys use debit cards, or carry much cash. They generally operate using credit cards, pay them off monthly avoiding all interest, and rack up immense awards. Reputation is a big thing with these guys too. They get pictured leaving a $10k tip, giving $100 to the homeless, getting over-quoted on a house, investing in certain stocks, buying frivolous shit, etc, and two things happen: professionals and plebs alike think they can take advantage as the info gets put in the permanent public record, and it sets a bad example for their kids. Most fortunes are gone by the third generation. But to answer your question, they do consider it a lot of money, for reasons different than you or i. Just my observations from what I know working at the CME.