Yea, i think selling bitcoin is a stupid decision because  the dropping market  is not suitable for selling bitcoin unless a financial emergency to the investor.The market predictions are telling that the year 2018 will be good for bitcoin.To the speculative market it is quiet common that such market corrections due to some other reasons it can go down till the next support point  After such correction it will come up gradually till the investors required level or above. Such dropping time the investor must have patience to wait till the price reached to his projected target.