It depends on your country, period.
Most countries, including the US, tax you on every exchange - not just when you cash out.
Say you bought BTC at $10k and
exchange for ETH today when the BTC is worth $60k. You’ll have a $50k capital gain even though you don’t have any cash.
This is true also for purchase. Say you use BTC to buy a car, with the same values as above. You’ll have a $50k capital gain on the purchase of the car. When you file your taxes after the end of the year (in the US) you’d report the gain and pay taxes.
Now, I'm wondering, if you continue with your example.
I bought bitcoin for 10 thousand dollars, then for this bitcoin I bought NFT token worth 50 thousand dollars.
( My profit is 40000 dollars )
Then I sold that NFT token for 10,000 dollars.
( My loss is 40000 dollars )
I have experience with tax returns and I understand that I can only report a certain amount of loss in a tax period and I will still pay tax, but how does this work in practice?
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I think the important point to consider is that If your losses exceed your gains in a given year, you can carry forward the excess losses to offset future capital gains. This simply means that you can deduct the remaining $40,000 loss from your future capital gains, potentially reducing your taxable income. Although The tax rate for capital gains depends on how long you held the asset. But I am not that much of a tax professional so it comes down to the law of the state or country.