Hi,
The way that crypto gains are taxed in France is very wrong.
While the formula is correct, the example is utterly broken.
  • The total acquisition cost should include the acquisition cost of the whole portofolio.
  • Once that is fixed, the actual cost basis is calculated at step 2. Gain is calculated at step 3. Step 4 is rubish.
To put it sanely :
When cashing 10% of your portofolio (2000€ sale price on a 20000€ total portofolio value), the cost basis is the same fraction of acquisition costs.
That is 10% of, let's say, 16000€. The cost basis is 1600€.
Then, the taxable gain is 400€ euros.
In order to be complete, the cost basis which was just taxed is to be deducted of subsequent operations.
Let's say that, the next day, 3000€ are cashed out.
The total acquisition costs would be now 14600€ (16000€-1600€).
The new portofolio value maybe dropped from 18000€ to 15000€.
The 3000€ sale price is 20% of total portofolio value.
The cost basis 20% of 14600€, 2920€.
The taxable gain is 80€.
I really hope that this is correctly implemented and that only the guide is broken.