My question is this: At some point I will inherit a lot of money, somewhere between 5 and 10 million dollars in todays money. My aim is to give it away. A few years ago I was made aware that it is unusual for charities to "grow" their money, since risking donor money is frowned upon, leaving charitable organizations with a large competitive disadvantage compared to other companies. This has always seemed silly to me, so what I would really like to do is something like make a trust (index)fund where something like 3 percent of the money was paid to EA per year. But I dont really know much about this stuff, I was wondering if someone here knows more about it. Is this smart? Are there funds out there already that are iron-clad? What is the best way to set up something like this? A trust fund?
So I think there are some preliminary questions here. (Please note that although I am a lawyer, I am not your lawyer and can't give you legal advice.)
The first question is: does the person from whom you would be inheriting know and approve of your desire to give the money away? If so, your first objective is protecting the money from taxes as effectively as possible. This is definitely get a tax lawyer territory, but it may be tax-advantaged for your person to leave the money to an appropriate charitable fund in their will as opposed to having it pass through you and potentially get hit with taxes. That would depend on where you live and how big your person's estate was. If the money needs to come to you first, you still want to talk to a tax lawyer about how to achieve your goals in a tax-advantaged way.
The second question is what cause area(s) you are interested in and your beliefs about what the future will look like, which will probably affect your views on the benefits of donating now vs. investing and donating later. I've not thought a lot about that, so will happily defer to others.
At least in the US, what you are probably looking for is called a "donor-advised fund" -- it is technically a separate charity that legally gains control of the money, but in practice allows you to tell it which non-profit organizations to re-grant it to. (That non-profit could either do direct work, or itself provide grants to others.) I do not think DAFs have minimum spend requirements, so it would be possible to donate 3% each year if that is what you wanted. You are not talking about enough money to make a private foundation cost-effective, and they have a required 5% per year spend requirement plus onerous paperwork rules.