What I am lost on currently is when to reevaluate the average cost of my BTC.
E.g., I buy some BTC at x amount, and make numerous daily purchases and sales of cryptos.
On each purchase I'm calculating whether the purchase itself was a gain or loss vs my avge cost per BTC. As, I purchase BTC @ 100 USD / BTC. The next day, BTC is worth 97. I make crypto buys and sells. If I use 1 BTC for a purchase, I' ve lost 3 on the purchase itself.
2 days later BTC is 110 and I use 1 BTC for a purchase. I've now gained 10 on the purchase (vs my 100/BTC avge purchase of the BTC).
It would take forever to recalculate my average cost per BTC on a daily basis.
But at what interval or what amount of increase or decrease should I start using a new average cost per BTC to calculate my gain/loss on the purchase?