PANIC SELL! no do not sell, if you made a good investment i.e. coin will be around for a long time, walk away and come back in 1 week. This is what kills new traders, there are people that specifically target this kind of panic selling. It works very well, they sell you coin and buy it back at a cheaper price. Do not fall for it. Expect that the price may fall or rise, you should be holding for a specific amount of time. Unless you are day-trading, in that case.. if you have to ask you shouldn't be day-trading.