It's their personal way of thinking to exit on their trades. As you can see, whenever their is a market's dump, their is a panic sellers and panic buyers. Short term traders just want to secure their fund by cashing out. We can't blame them. Greedy or not, the first thing a trader think is the profits that they will gained once the market is on their way or not. Let us not be affected with those if we have a major goal in trading.