They could lose 90% of what they have and still be comfortable for the rest of their life.
And the only reason their money depends on factors like the value of companies is because they want to add to the pile. It could literally be a pile of gold if they wanted it to be, that's just not the best way to make it grow. More realistically, it could be invested in index funds or something similar that the administration can't selectively destroy.
Worst case the government finds a way to confiscate everything, or imprison/kill them, in which case they're exactly as vulnerable as a normal person.
And the only reason their money depends on factors like the value of companies is because they want to add to the pile. It could literally be a pile of gold if they wanted it to be, that's just not the best way to make it grow. More realistically, it could be invested in index funds or something similar that the administration can't selectively destroy.
Worst case the government finds a way to confiscate everything, or imprison/kill them, in which case they're exactly as vulnerable as a normal person.