When you look at the prices of cryptocurrencies you can see people have bought at really high prices. If you have bought $1000 worth of DeepOnion for example at the price of $19 then you would be left with $86.42 worth of DeepOnion right now. But even at these low prices right now you can still see lots of dumping going on. Logic would tell you to buy as much as you can at these low prices and hold for the next bullrun but the opposite is happening. There are some ups these days but it get's dumped very quickly. I believe we haven't seen the bottom yet.
This is called panic selling and FOMO. People are not able to exclude emotions from trading. Usually when a price rises, people buy in FOMO (Fear Of Missing Out). When the price dumps, people sell out of panic. There is nothing wrong in buying during bullish period. But you need to time your buying and never buy at ATH. Similarly, there isn't anything wrong in selling during bear phase. But again panic sellers end up selling at all time low. Buy and sell can't be timed without a knowledge of Technical analysis and most of the traders here don't know much about TA.