This is considered as one of the effective strategy in the market. When the market experience to red, some investors sell their coins because they thought that it can't recover from the fall. But actually some investors consider this as an opportunity to buy low price coins and hold it for long time. They wait for the right timing when to sell the coins at higher price. By this we can say they gain more profit because they buy it in low price and sell it in higher price. Risk is just part of doing business. Although this strategy is risky but we can't gain more if we don't take the risk. And some strategy that proves gaining more in this business is holding of coins and waiting for the right timing when to sell coins.