Here's the key sentence which roughly translates into "Losses are not deductible" > "Sopimussuhteeseen liittyvät menetykset eivät ole tuloverolain mukaisessa ve

Here's the key sentence which roughly translates into "Losses are not deductible" > "Sopimussuhteeseen liittyvät menetykset eivät ole tuloverolain mukaisessa verotuksessa vähennyskelpoisia." Additionally, Example 3 is given to show how an actual loss of 500€ is not considered a loss in taxation and is not deductible. The Finnish tax authorities use a First In First Out principle in crypto taxation. So if you buy 1 BTC for 10€, and later 1 BTC for 1000€, and later sell the 2 BTC for 20€, you have to pay taxes on the 10€ "profit". Even though you lost 990€ on the second BTC.