Welcome to the world of trading,you dont sell the coins because you saw a steep fall in price,ripple does have an acceptance in the Japanese banking system and there is no doubt that the price would recover in the future,so you can either buy now and average your price or wait for the long haul.Hope you have noticed that all of the alt coins went down today.
I state again, long term investments are the safest. If you invest short term you might find yourself in the situation of selling when you shouldn't and buying when you should've sold.