it depends on what you are trading and when you enter too.
for example long term investment in bitcoin, yes it is most profitable especially at this point when bitcoin is rising over time.
but in some altcoins it is not recommended at all. for example eth may rise in the future (long term) but also there is a huge chance that it fails and because of the two chains dies in the long term.
As a bottom line, bitcoin investment is really meant for long term investment. With the established name of this coin, it will really take you for a success one in the future.
Unlike in altcoin, where obviously just for short term profit.