Supermillionaires are people who have a super lot of money, even more than regular millionaires.
Being supermillionaires is usually seen as a very good thing because it means they have a lot of money and can buy many things.
Examples:
The supermillionaires have so much money that they can buy anything they want.
There are only a few supermillionaires in the world.
The supermillionaires give a lot of money to help others.
The supermillionaires have so much money, they could buy a whole country!
The supermillionaires have more money than anyone else in the world.
The supermillionaires are so rich, they could buy a super big boat and a super big house and still have lots of money left over.