Many people fail in trading atimes because they lack the ability to access, evaluate,and examine the market situation at that time.They are only focused on putting money in it,and won't care about checking whether the time they want to invest in the market is the appropriate time or it's a wrong timing.
As we all know that trading is something you don't just rush to invest your money in,it is something you sit down to analyse critically,and and have a proper check to see that if you are putting in your money,it isn't going to go in vain.
Another term that is suitable to describe the expression you said is some traders who do not know when to enter the market to trade or others and when they should exit with the aim of saving what they have earned through the market. Because if a trader does not understand these two things, I think the trader will always lose more and lose with his own actions because he does not have the knowledge to read market trends so he enters the market in bad conditions and does not exit the market when conditions get worse.