It's very possible making a big living by trading crypto/altcoins alone.  I have few numbers of people doing full time job on crypto trading.  However, they do it on a big scale, they invest around $5,000 daily, and they get range of $500-$1000 daily ROI.  Anyone that will do such must be vast in trading knowledge and experience, because as you can gain double of your capital so you can lose everything within few hours.