I made an application in 2013. I have all these judgements, spoke with tax specialists and big lawyers firms in the Netherlands, spoke with the tax office Rijnmond which is the ONLY office in the Netherlands that can make rulings. The judgement you speak about had as only purpose to save a lot of money for the Dutch Governement. If this man would win this proces ALL dutch investors that make losses would be able to deduct these losses from their income. It would cost a fortune to the Dutch Government. So the judge had no choice, it was a political judgement. But what is so dangerous is the arguments that the court used. According to lawyers I contacted there is enough room to make the interpretation in such a way that someone who would declear a few millions would have to pay 50%. Laws and judgements can be used in many ways, that's what lawyers do, but also tax people. Famous Dutch lawyers told me that they could not give me any garantee that I would not pay more than 1,2%. I asked at the Ministerie van Financiën to confirm me that according to the judgement that you refer to I would be taxed in Box3 which means 1,2%. They refused to confirm, not only in writing but also verbally.
I read the internet too, but if what I read is not confirmed by real specialists, then I don't trust the internet.