I don't know what but something about the letter made me feel like either he is planning to retire next year or something else is wrong. Could be why he has raised cash to over 325B.
Also +1 for Doctors Without Borders.
I also suggest Sankara Eye Foundation. https://www.giftofvision.org
Last one is Direct Relief https://www.directrelief.org
Imagine if the idiots in DC allowed Investing social security funds and other government funds in the stock market like the Norway and Singapore sovereign funds would the USA even need to take on debt.