The situation of market at this time is more reasonable to buy than selling. Some coins may have little profit when you trade for short term. If you are planing for long term, shouldn't sell
You're right, a lot of coins fall so deep at the moment, for example look at ethereum which fell more than 50%. it is will be a good way to start gain awesome profits. It's just to hold it in the long term, some people are not patient enough to do it.
True for comparing it on the past price that hit on the highest price and as of now it was deep so hard that is why we should have to decide buying and be an owner of this currency that are very well known for being some of the good currency on.