You take a monthly average of the coin cost(you can do daily if you want but so far its not needed). Let's say 100 low - 200 high. Avg monthly mining is 150. If you sell the coin for 120 then you take a -30 cap gain hit.
I am 100% sure on this as I have been audited. ASK YOUR ACCOUNTANT anyway.
Also they ruled that crypto IS property and not subject to wash rules. I just did that to take a neg equity hit because prices are so low. That means I sold all my coin at a loss and rebought them all a few min later. Perfectly legal. Wash rules apply to stocks etc, you have to wait 30 days to rebuy.
Thanks this is good advice, from a man that runs a farm and speaks from experience. I'll probably do something similar when doing my taxes
This is bad advice...
Any bitcoin gained through mining is taxed as ordinary income, based on the fair market value of the bitcoin at the date it was received.
Read the irs publication on mining.. anyone who has mined and held is at a huge loss in 2018