Most of the investor and coin reseller sell their token with a loss because crypto market going down and down. Last bitcoin price crushed and than bitcoin broken all previous record but the end of the last year price going to down but i am still believed bitcoin will back place and market will be up soon
When emotions are involved then you will definitely go sell off even if you don't gain or even loss some amounts from initial investment. That is why before you engage in crypto investments, you need to understand its nature and have faith in the technology for a peace of mind and might as well do a long term investment.
Best thing is only invest what you can afford to lose. After that less likely to make emotional decisions. Only time I sell is to short it and gain more of the same coin

Yes that should be the best thing to do but we are just human beings we do have emotions that sometimes are affected by environmental factors just like FUD, market fluctuations, and many other factors that could make us do bad decisions and regret it in the future.