Everybody is thinking of this and nobody knows exact when the perfect times are but a general tip like this can help. When Bitcoin price surges up more than looks normal sell some, and when Bitcoin price downs bigger than normal buy some, with that simple advice you will get closer to the tops and bottoms and through trial and error you can probably figure it out.
Holding a bitcoin is just like waiting for a big chances to earn a big profit, because if we are going to hold and wait for the right time to sell we can select a good price in order for is to gain a good profit. Holding is said to be the most common yet profitable strategy and it is advisable by an expert so then I suggest that we must hold for good.