J'ai trouvé ceci écrit par un avocat californien, où tout ce que vous me dites semble démonté et notamment ce que vient de dire meuh, c'est inquiétant, je vous conseil de lire l'intégralité du lien, pour les plus flemmard j'en extrait deux lignes :
https://www.reddit.com/r/Bitcoin/comments/1uccfz/i_am_a_tax_attorney_here_are_my_answers_to_the/"THE AUTHOR Tyson P. Cross is a tax attorney licensed in California and Nevada."
#2: When do my gains become taxable?*
Gains are taxable in the year they are realized. Realization occurs when you exchange bitcoins for any type of other property; such as cash, merchandise, or services. This includes everything from haircuts to yachts. Essentially, any transaction involving Bitcoin is a realization event and triggers taxable gain. Note: IRS Notice 2014-21 expressly confirms this treatment.
#3: What if I sell my bitcoins but do not withdraw the proceeds from the exchange?
It doesn't matter, your gains were realized the moment you sold them. It is irrelevant whether the proceeds from the sale are kept in your bank account or your exchange account, you still have a realized gain for tax purposes.
Cela est valable pour les usa, cela serait-il donc entièrement faux en France ?