It was a very good idea if you did on december 2017.
Right now i don't know it is good or bad, the time will tell us for sure.
But if he/she is late to join in the crypto world and he buys at the high price, I guess he cannot stand on his foot because it will make him frustrated like many of us.
I wonder what he/she was doing right now. I hope he is not selling all of his altcoins and only sell at the right time. I know how he's feeling to see his coins value down deeper, but I don't agree if this makes him desperate and don't want to wait for a while.