system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is Bill Gates still the third richest person in the world?

Considering his work with the Bill & Melinda Gates Foundation, the Giving Pledge etc. plus divesting himself from Microsoft (for the most part) how does he stay near the top?
gpt
It's because he has so much money, and money makes money.  When you have $100 billion and can earn 8% a year on it, you can give away $5 billion a year and still add $3 billion to your net worth every year (and it compounds from there).  He actually has about $118 billion in holdings, even though he's given away nearly $40 billion to his charitable foundation.  And he has an entire captive investment firm working daily to maximize the return on his wealth - this team knows how to uncover and pounce on opportunities, how to minimize frictional costs and taxes, etc.