Thanks for all the answers! So far, they basically mirror my thought processes.
One stock that might fit the bill is Berkshire Hathaway B Shares (WKN: A0YJQ2). They should be liquid enough, even when traded in Germany.
Yes, they were actually the number one candidate I had in mind.
Overall though I'm not so sure, that this is a good approach, to let the tax tail wash the investment dog. What would happen, if the stock drops 30% or 50%, after you buy it? Do you understand enough about the company to know, whether to hold or to fold?
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You have to buy a company you like because you are putting money at risk. So no.. let it go unless you are planing to hold something for a while. My stocks could take a 50% hit and I wouldn't sell or be too concerned but Im in high conviction securities right now.
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That's also something I wondered (and why I left open the possibility of not doing anything at all). I suppose the question is whether the increase in risk over the pure indexing approach is worth the additional tax savings. I am currently 50:50 on this.
I should say that I would have no problem holding the stock for 20 years (or longer) if necessary, so a serious drop would not make me sell. But you are right that it would need to be a company I have sufficient trust in. Berkshire Hathaway would be such a company and I do also like them -- not that that actually means a lot.
What's a high conviction security, by the way? Somehow my mind jumps to investments in prisons... I suppose that's not it?
For Germany, I like Allianz. Solid company.
I do also think that they are solid (again, not that that means a lot, coming from me). Of course, they do pay quite a bit of dividend. I actually hate making investment decisions based on the method of distribution a company happens to have chosen. But for this case, it's fairly critical...
I don't really care which country the company would be in, by the way.
See... what did I tell you

That's incredibly cute ;)
And if you buy into the notion that you should invest in companies that you notice in your daily life (I am not sure where I read this), he is probably a much better investment expert than the ones we see on TV.