So can you get unrealized capital losses to turn into tax credits? And can a person build up these credits to use in different years? If not, this is just a big tax increase to support continued government inefficiency instead of fixing spending and efficiency problems.
Yes, losses can be carried forward indefinitely:
> Losses within box 3 can be carried forward indefinitely and offset against future box 3 income. However, losses cannot be offset against income in other tax boxes in the Dutch personal income tax. To avoid administrative burdens, a minimum threshold of € 500 applies before a loss can be officially recognized.