international setup

Hi, you are at a good start here. If he is a day trader, he should have transaction history as proof of source. Where is he based, is such income taxable there?

In order to invest the funds in to real estate (or what property he wants to buy? gold?), he will have to off-ramp it first, depending on the country. Also, he needs to be aware of the fact, the real estate always follows local laws for taxation, no matter what taxes are concerned. If he invests in 200 countries, the administrative burden is huge. And on top of that, he may have to own it in various local companies or personally. All real estate is subject to local inheritance tax.

And then what do you mean by safe and untouchable? Crypto is untouchable. Real estate, you can just go there and put your hand on the wall of the house and touch it. Pretty much anybody passing by can touch it. And you should really consider this analogy, by far not all countries recognise trusts and real estate is subject to various taxes where it is located. And it is not safe either as it is immovable, if the attractiveness of a location goes down due to political changes, your investment will be null.

While I personally do not see much gain from moving from crypto to real estate, particularly late in life, we are happy to help.

It is a problem that all gains so far have not been reported and taxed in Germany. He may move to Andorra and keep doing his day trades there in an attempt to hide the real source over the next decade.

Business income in Germany, is most likely reported and taxes have been paid on. This is easier.

I guess the best way is to first get somehow clean with the money. Andorra etc. may help on that. While you probably could start with trusts, etc. I guess it may be easier to just move out of Germany with his kids and then legally inherit the wealth without inheritance taxes. Trusts can work, but I guess they will come under much scrunity over the next decades. CFC rules, etc. are waiting. In case he or the kids live in an unfavourable jurisdiction, the whole trust can easily fall to taxation in that jurisdiction.