Right now bitcoin price increase is getting continued for a long time. This gives every user an added profit. Bitcoin grows gradually, which describes that holding doesn't have any specific time. Everytime holding is effective.
Yeah for this time i think holding bitcoin is very good because there is some people predict that for this year bitcoin will halving.
You are already off-topic mate since you do mention about halving. The next halving wont happen next year but in 2020. Better search off what is the true meaning of bitcoin halving. Holding bitcoin is really effective if you do have lots of money or bitcoin to invest but some do like to see profits on short term basis thats why they make investments.