Yes, this is a foolish decision. Although many people think that the price of bitcoin is very high now, I think bitcoin will definitely increase in the future.
Most of the people do that mistakes. So people get more loss. People before start the any process. First learn the information. Then invest. Before buy and sell you know the all coin price list. Coin price is not stable. So it any time to change the price. If want for the price information check the market place day by day. Then easy to get the price list every day. It good future saving. So hold it. Then sell.