How I should pay tax if I buy Bitcoin from an overseas friend Assume I buy 1 bitcoin from an overseas friend which is USD$10 and I sell it in US for $11.


is it legal? I am afraid, it would be considered money laundry
I will not be able to have official receipt from my friend, do I pay tax as for the earning of $1 or sell price $11?
The $1 is a Capital Gain (it's not income except perhaps if you're a professional trader). So, if there's tax to be paid, it will be Capital Gains Tax, not Income Tax. When you declare your total Capital Gains and your total Capital Losses to your tax authority, they will tax you on any net gain over and above your personal allowance (which will depend on your personal circumstances). See https://www.irs.gov/taxtopics/tc409.html