Those off-shore accounts are still invested. They don't let their money sit. The real estate is in the form of shares in real estate holding companies. They are taking a beating too. The price of real estate itself is also going to take a beating.
Some rich will get richer very soon, but many will lose money. I have a little cash in the bank myself. Not much, really. But I plan on buying stock with it when it looks like we have hit bottom. There was one billionaire in particular who is known for having bought with every penny he could get his hands on after the '29 crash. I can't remember who it was. I'm sure there were plenty who did. All those who had actual money instead of virtual fortunes that were wiped out by the crash.
But - as it stands today, there is an awful lot of money that has disappeared in the last 3 weeks or so. Where do you think our millionaire hockey players have their money?
If they are smart they have some in the bank, some in investments, some in tax free accounts and some in real estate. If you are diverse enough with your money you can survive something like this. If you had every red penny in stocks you deserve to lose it all.