In the states I'm familiar with, that's largely just gonna cover pre-existing assets, and you need to be talking about a large initial discrepancy (millions or more) probably to make it worthwhile. I've also been advised that it's easier to do something more like "the prenup will say you'd get 10%, but you revoke your claim to trying to get more" than some sort of "it's all mine!!" - it needs to be non-coercive and give both parties consideration and a reason to make the agreement. Lawyers told me that there's a often a big difference in that world between "what a lawyer might be willing to write up and get people to sign" and "what's gonna hold up in court."