Say you have €80k in investments. Markets go up, in one year time your investments are worth €90k. You did not sell.
That means you had €10k in unrealized capital gains. Subtract the €1800 per person threshold. €8200, 36% tax is €2952 tax to be paid at the start of the year.
Losses give you tax credits redeemable against future capital gains (not against income tax from employment)
Unrealized capital gains taxes are crazy all in an effort to own the rich or something. Meanwhile the people they're perceived as targeting have all the resources to avoid it.
I don't know about non-publicly listed companies, I assume you indeed need to appraise yearly.
The rich don't pay these taxes as the unrealised capital gains tax is only for private individuals, not companies. The rich have their assets in companies / shells.
Well, that's how it used to go, anyway.
Paying tax on money you make because you already have money is far better than playing tax on your time you sold for salary.