Example:  How to enter transactions if I transfer a coin from my exchange to my wife's exchange and we both file taxes together?

You have the option to enter the withdrawal as (OUT) gift and the deposit as (IN) gift, however both transactions will then be listed in the respective donation and income report of the tax report with the value at the time of transfer. While this work around ensures correct cost bases for the coin in the new account and taking it out of the purchase pool in the sending account, please ask a tax accountant whether it is legal to then omit the values from the donation and income report in the tax total.