You get to keep only enough to maintain a very modest lifestyle in a low-cost-of-living area, the rest of it has to go towards improving the world in some way.
Edit: Given the previous rules that you must maintain a very modest lifestyle in a low-cost-of-living area, would you rather choose to opt out and not have the money at all?
If the Big, Beautiful Bill in the US gets passed in the Senate with the provision requiring plaintiffs to put up a bond to sue the government over these illegal actions then I’d be bankrolling every citizen and group that is interested in suing to fight them, including putting up a bond.