What would you do if you had $1 billion?

Ideally start a foundation with a good portion of the money - ensure I am remembered after my time for doing some good and helping people. Say a few hundred million to that cause. Then, I’d like to try my luck with running a fund with a decent size. Another couple hundred mil to this. This of course doesn’t even come close to the size of big hedge funds, but it’s enough to still really make some moves. Then, we’ll say I have $500M left after that. Ideally with this I can do whatever I want. Collect my $25M per year in interest assuming a conservative 5%, and really ball out. If I’m a billionaire, I’m getting some nice places in ideal locations. Thinking Swiss Alps for skiing, south of France, penthouse in Manhattan, Mendoza region of Argentina, somewhere on a Caribbean island, and Hamptons just off the top of my head. I’d also love to have some cars I’ve always dreamed of owning. Big list, but the big ones would be Audi Quattro Group B car, Ferrari F40, Jaguar XJ, old Camaro and Mustang, a nice ‘80s Chevy squarebody, McLaren F1, and some old formula car. Of course, all of this spending is after I get my parents anything they want and set aside enough for them that they don’t ever have to worry about anything ever again.

Alternatively, 1 billion dollar parlay

Buddy, 1 billion is already more than generational wealth Honestly would find a way to give back to the best of my abilities using the capital

Double it and give it to the next person in my family

Your friends are idiots.  A billion dollars is way beyond any "generational wealth" standard.  A single year's worth of passive income from a billion dollars is generational wealth, quite honestly.

I'd put put $750mm into a DAF right off the bat and hire some folks to help me give it away in a sensible manner, and then put the remaining $250mm into a series of passive investments and live off the income stream.  Any residual from that interest goes into the DAF as well.

I don't think I'd want that much money to be honest. What people fail to appreciate is when you are that extreme level of wealthy:

1) You don't know if someone is trying to get close to you because of money. Even if you don't flash it (cars, jets, yachts, etc) at all, then at that point it's still way too much money for simple financial & psychological comfort to just let it sit and compound in the background

2) Your life becomes about defending that money as someone is always trying to get a piece. Life is transactional. Even with marriage, you wonder what happens when you have to give a couple hundred million / billion in case of divorce (which is 50% of the time). Hard to trust 

3) You have nothing to strive towards. Sure there are passion projects but at that extreme level of wealth, motivation becomes ridiculously hard to sustain over long periods of time

4) Vices become far harder to avoid. Whether that is women, drugs, etc you can buy anything you want....while the moment will be fun, that's a terrible set up for long-term happiness 

Not to say that 2nd-gen billionaires can't be happy, but you're threading with a really fine needle with a lot of things that can screw it up. Bill Gates really said it well, which is that he wants to give his kids enough so that they can do whatever they want but not so much that they can do nothing. That's in my mind right balance between pyschological & financial comfort vs. living an authentic, meaningful life

What's that number? I think if I could give $5ml post-tax to each of my kids when I die (in today's dollars) and maybe have another $5ml left over after that as a fund for expenses here and there (beyond regular income) that would be more than enough -- I'd donate that last bit to charity when I die. So with 3 kids, I'd say ~$20ml in today's terms which in 30yrs let's say would be $40ml assuming ~2.5% inflation. Frankly though my gut is that this number is an overshoot if anything

I guess I never answered the question, though let's assume I have just $20-$50ml -- I'd do everything I'm doing now with the exact same lifestyle, except for buying a nice house. And in 10yrs I'd start my own fund. Those are the only major changes, I'm very happy with my lifestyle as it is 

Fund a bunch of music production for myself, and fund a bunch of other cool music shit for other people

Buy a neighborhood and move my my closest friends and families in

I'd throw it in treasuries while rates are high and then I'd figure out exactly what I'm passionate about. I'd also be inclined to open a Charitable Remainder trust because it would allow me to put a certain % for income and give the rest away to things that are important to me. But like others said, the income off $1B alone is absurd. $1B earning 4% is $40m/yr. 

Step 1: Buy a Pagani Zonda

Step 2: Quit my job and buy a bunch of land, and use it to spend the bulk of my time running a dog rescue where they have tons of free space to roam around until they get adopted. "The Asher House" is a good example of this - I'd love to get a bit more ripped like him too lol.

Step 3: Go back to school and get a degree in something interesting but generally unprofitable like international relations / public health.

Step 4: Political career.