This is SO hard for me to internalize though! I think there are times you want to focus on the dime and not the satoshi, but the more I see the more I believe those times only make sense if you are buying BTC to go straight into the other asset.
I track both the USD cost and BTC cost for all my trades just in case and sometimes go back to muddle through the data. Tracking ROI is so difficult with all the constantly changing numbers that go through it!
Whats your solution for keeping track of your trades/cost basis?