I used to daytrade crypto's back in 2011-2014, and back then I did actually make a living doing things like arbitration trading of price differences between exchanges. Now there is ofcourse a ton of bots doing that and no place for a manual trader like me. These days I just buy and hold the cryptos i believe in for the long term.
I was interviewed in a Norwegian magazin several years ago because I was for a short while living of trading cryptos, have a look here if you want:
https://steemit.com/blog/@xtetrahedron/kryptisk-verdi-a-norwegian-interview-i-was-featured-in-about-crypto
I made a bot trading at bitcoinsnorway.com - earned a fortune on it as the order books were thin and shallow, the average trader on bitcoinsnorway.com was rather inexperienced, and every now and then someone would place a large buy-order without realizing how much that would affect the local market price.