Nobody wants to be monitoring the prices all day with the cursor on the sell button just waiting to click the mouse, so how do you decide when to sell?
If you set up an open order with a low target price, you'll be disappointed when the price climbs well above your target price.
If you set up an open order with too high a price, you might not sell at all.
What's your strategy?
You should have always target price for you to consider that it is now the time to sell your coins. My strategy in trading is I buy a coin when price is low and I will sell it if the price of the coin exceed in 10%.