If this time is the lower price of top 20 coins. You can buy it now. But its not easy to predict when this coin price will stop to fall. I think you buy it one or two days later. This market still red in this time
It is better to keep buying if the price is low and hold until the right time which the price will getting higher so that we will be able to achive of earning big profit. Those xoins is very helpful and useful as always becaus eit can be use in different transaction.