Warren Buffett's net worth is $89 billion as of Jan. 30, 2020 and he has promised to give away 99% of it.
Most of the Buffett estate is already earmarked for charity. Since 2006, Buffet has donated approximately $34 billion to charities. The bulk of it has gone to the Bill and Melinda Gates Foundation and charities named for his late wife and his children. On his passing, a large portion will continue to go to the Gates Foundation as well.
Buffet will give away all of his Berkshire shares through annual gifts, 10 years after his estate is settled. And there is a reason he is giving away stock as opposed to cash. When an individual donates stock, they receive a charitable contribution deduction based on the fair value of the stock. This way, he avoids having to pay tax on the capital gains of the stock if he were to sell it and then distribute the cash.
Buffett has left considerably less for his children, reflecting his expressed interest in promoting self-sufficiency and strong work ethics among his family. The bequests to them include Berkshire Hathaway stock and some real estate properties. His personal philosophy on this is, "...a very rich person should leave his kids enough to do anything but not enough to do nothing." They will also be receiving over $2bn in stock, over time, for their personal charities.
Buffett is a proponent of a bigger estate tax on wealthy individuals. Alongside George Soros, he has called for a dramatic increase in that tax rate. His decision to give away the majority of his investments to charity is a reflection of his personal beliefs about wealth and taxes. He has also started the Giving Pledge with Bill Gates. The goal of the Giving Pledge is to have extremely wealthy individuals commit to donating 50% of their wealth to charitable causes upon their deaths. Individuals that have committed to the pledge include Mark Zuckerberg, Michael Bloomberg, and Richard Branson.
On the subject of how his estate should be managed after his death, Buffett hopes to contribute his stock to charitable causes and have the remaining cash portion invested in passively managed index funds that are relatively safe. Having gained his wealth from stocks, Buffett has said he believes the value of his estate would be best maintained using the stock indexes – specifically, those mirroring the S&P 500.
In fact, of his remaining wealth after charitable contributions, he plans on investing 90% of that into index funds and 10% in government bonds. This method of investing will primarily be for his wife. Buffet has always been a proponent of passive investing and believes index funds bring diversity, low-cost fees, and access to the biggest companies. "There's been no better bet than America," says Buffet. He also believes that investing in index funds will do better than any portfolio manager or financial planner.
Though being one of the wealthiest men in the world, Buffet has been able to maintain a humble and grateful attitude towards his lot in life. This has been represented in the modest way he lives, how he has raised his children, and how he has decided to distribute the bulk of his wealth to charities upon his passing.