i usually wait till bitcoin price decreas really hard so i can cash out all my bitcoin while its on high state and buy many bitcoins when the price is too low like last year where it hit atleast 500$ and im thankful because i found bitcoin as a profitable way and legal way and also i found that bitcoin price is constantly raising.
that is very nice but i think it is not such an easy job to predict about the price of bitcoin that when will it start increasing or going to decrease. i think only few expert can give a good prediction about the price of bitcoin, but still they also do no sure about their prediction because of the nature of bitcoin.