That depends on the tax jurisdiction and circumstances.

In the Netherlands, appreciation is immediately taxable for individuals, but not for corporations.

And what about depreciation?

How does that work in practice?

I presume you don't send a cheque off for €1.36 at the end of the day, (or receive a cheque back after 8 months)

You pay an annual % tax on the value of your investments less debt as of January 1st. This means you still pay taxes if your assets lose value, too. It's a wealth tax that pretends to be a capital gains tax.

Ok. I'd quibble about it being a capital gains tax at all, but anyway.

It doesn't pretend to be a capital gains tax at all. It's a tax on income from assets, which is in practice more or less a 'wealth tax' which is also why it's called the Dutch word for 'wealth tax' in the first place.

It is a tax on an assumed return on assets, determined as a set percentage of wealth. "Vermogensrendementsheffing" means a "tax on return on wealth", not on the wealth itself. In name it is not a wealth tax, but in reality it is, since the assumed return that is taxed has no relation to the true return. This relates to the recent decisions declaring this partially unlawful, see e.g. https://www.tilburguniversity.edu/magazine/supreme-court-net...

You should probably amend this, since this is very misleading to people unfamiliar with the Dutch tax regime. As you are aware, in the Netherlands net wealth (not capital gains / appreciation) is taxable. (Even if you consider the appreciation consequently also taxable, it's certainly not immediate, as the wealth is only assessed once a year).

With the upcoming vermogensaanwasbelasting they'll tax actual gains on stock appreciation.