Yes, it's possible. 
And you are right BTC/USDT is the best pair to trade. your are least affected by the fluctuations in BTC price against the dollar. to make 50$ a day, would require a generous amount of capital. $1000 in BTC at least. Some exchanges offer leverages which give higher profits but also come with greater risk. Good luck
And you are right BTC/USDT is the best pair to trade. your are least affected by the fluctuations in BTC price against the dollar. to make 50$ a day, would require a generous amount of capital. $1000 in BTC at least. Some exchanges offer leverages which give higher profits but also come with greater risk. Good luck