We don't know the structure of "The Earth Fund" so here are some possibilities: if its an actual fund then it can make more investments, no immediate tax conse

We don't know the structure of "The Earth Fund" so here are some possibilities: if its an actual fund then it can make more investments, no immediate tax consequences, but any long term capital losses, because nobody has a sustainability solution that makes any money, will serve to offset any taxes that he would have to pay on the long term capital gains of his Amazon stock sales. if its another charitable foundation, then the whole $10B will offset up to 50% of his whole tax bill any year, rolling forward till there is no more to deduct. not just limited to any particular type of capital tax. he can also just donate his amazon shares without selling them first, gaining a charitable deduction on the entire value and no capital gains tax event, but depending on the type of charitable foundation the donation could be limited to his cost basis, instead of the current fair market value, another consequence being that a lower % max deduction is possible. Actually this could be genius because his cost basis might have become pegged to the fair market value in the divorce. The IRS allows divorcing couples to keep their original cost basis on split property but could be optional, given the nature of their settlement where it seems there were modifications onto what the stock contract actually is - with some shares transferred but voting rights retained. So for example, there is almost no scenario where Jeff Bezos has to pay any taxes on the $4Billion in Amazon shares he sold earlier this year. Whether he converts another $10B shares to cash or not. So even though he 'spends' on a cause and theoretically doesn't get to use that money for himself, even though its not paying the government either, he doesn't actually lose any money he ever actually had. It's nice that a transaction towards this cause is occurring.