Fear : Fear can cause investors to act rashly, such as selling off stocks in a panic, when markets are down or there is uncertainty (such as during a financial crisis). Because the market may eventually rebound, this practice, known as panic selling, frequently locks in losses.Fear : Fear can cause investors to act rashly, such as selling off stocks in a panic, when markets are down or there is uncertainty (such as during a financial crisis). Because the market may eventually rebound, this practice, known as panic selling, frequently locks in losses.Fear : Fear can cause investors to act rashly, such as selling off stocks in a panic, when markets are down or there is uncertainty (such as during a financial crisis). Because the market may eventually rebound, this practice, known as panic selling, frequently locks in losses.