It is true that we are seeing many altcoins going down at a very high rate even in a short time period. At this point, the most important thing to do is doing a very good research. Because there are really small amount of altcoins which can be trusted for HODLing.
Its been proven that not all altcoins are capable of enduring the dips, some once go down weren't able to go up again like what happens in many ICO projects before who turns out doing exit scam. Better watch out for all the coins your holding or move into safer and trusted coins that endure already many dumps but able to cope up after.