In my opinion, the one thing that needs to be done the values of the coins that you have invested in are dropping, simply continue holding. Don't ever sell your coins for a loss, since you might end up making it a habit. It won't hurt to hold on to your coins until their values recover and then sell afterwards.

I think investors should try to understand that the market is so volatile, prices go up and down and that is how it goes. It is totally up to an individual to decide when to sell, however, it is not advisable to sell when you are not making profit.