Forbes 400 ricchest Americans

For the first time wealth of each participant in the list is at least 1 000 000 000 US dollars

Where the wealth is?

The level of gross foreign claims on U.S. assets is approaching $14 trillion, about 25 percent of U.S. wealth and perhaps 10 percent of global wealth. Eventually, foreign investors would become reluctant to own, say, the bulk of U.S. assets or to have the majority of their wealth holdings invested in one country. However, we are far from such limits for two reasons.
Followign that logic, the USA is home for the 40% of global wealth.
Source - America's External Balances Economic outlook
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From sea to shining sea...'