My method of closing instrument holded longterm (as investment) is to not seek the top, but if You see drop from All Time High (in my drawing i got 10000USD for BTC but it's for example only, not a prediction of price!) deeper than 38.2 Fibo (especially on closed Daily and Weekly bars) You should close part or whole holding after bump from levels below 0.382 (and this bump should be minimum 0.5Fibo or more - measured from All Time High to dip).