That's right people who will get panic and will sell for the low price then they will definitely regret in coming days when they will see the higher price of bitcoins so its better to hold them for a long term and should not be worried about short term fluctuations.
But if you look with recent pump nowadays like ICONOMI right now. short term fluctuations has benefit for you if you can handle it well.
If you hold it for long term, when the best time to sell it if you do that?. If you see the price is going up, you could sell it half and the rest you can keep for hold again.
That is the right strategy to follow as holding too long can also be risky as if price goes down then you will have to wait longer for making profits so its better to sell some part of it to grab the profits and rest should be saved for the future.