There are many coins that best in trading as long as you know that the coin that buy is really legit coin because there are many coins even the volume is too high then price will not increase and that is a scam coin. You can do trading on poloniex sir because all of its exchange is real coin and it is on the top 100 volume coinmarketcap but mostly you can earn only 20 to 50% profit. For me, the best coin to trade is upcoming coin.