In trading bitcoins, all you need is time and patience. As i see today, bitcoin now is dropping and that is the best time for you to buy bitcoin. Then observe the graph if the bitcoin rate is increasing up to your desired value then that is the time best for you to sell it.
That's right, Bitcoin has declined in price for now and it's time to invest it.
BTCI think that it is better for you to buy bitcoin if the value is low because the bitcoin value will always go up again. So that best thing to do is wait and see what happens. And if you think that the value won't go higher then just sell it and continue the cycle till you are rich.
When you a lot of money and want to invest in bitcoin and when you need money for your daily needs or something else that will be the time for selling your bitcoin.
I think without any certain reason and intense need selling someones bitcoin is a foolish idea because it is a business and if someone withdraw his investment his earning will be reduced and he will make less or money. Therefore I think holding is better than selling.
Every time is good for buying bitcoin and selling. But the best time according to me for buy bitcoin is when the value of the bitcoin is fall down and the rate of falling is low not very high. While for the selling of bitcoin you will make sense of the market and then you will decide that is it god time for selling or not. For me when the value of bitcoin raised rapidly in short time and then become stop rising that time is a good time to sell.