The value of bitcoin and other cryto currencies are unpredictable, you should always monitor its value from time to time. Some of it may increase and some of them will decrease. Absolutely correct, sometimes our greediness may lead to the loss of our chances to have a good profit. We we're trying to wait its value getting high, if you feel its value is quite enough its time to sell it as soon as possible.
In order to overcome some of fears in holding be contented if you feel its a right time to sell to have a good profit. I believed that there is another chances to gain more profits from other crypto currencies which you try to hold.
You need to make yourself understand this thing that there is nothing good than that of holding and if you will hold your bitcoins, you’ll be rich one day.
but if you have skills in trading, you can prevent the risk so you can make a profit in trading. I think no matter you have skills or not, if you can manage your emotion in trading, then you don't have to fear of holding a coin even if you are getting stuck in a high price because you just need to wait the price is back to increase. if you have many experiences of this, you can easily prevent your fears inside you and you can stay calm when the price is suddenly out of your control.