its hard to explain lol,  each coin is dif.
There are many signs a few are, momentum, buy support, sell side, the overall mood sentiment towards the coin and lots more.

Its very dangerous for people to take alot of regular profit , when a coin is so undervalued esp when its $500 bitcoin...you just get taken out.
Best not chart watch too much and read more into why bch is the real Bitcoin then you will learn its true value, bitcoin is powered up and cheap as fk ..wow lol