My eyebrows went up when I read "It was early 2017." I'm pretty sure I remember chatting about this at work in 2013 or very early 2014 and even then my understanding was that it was too late and that automated cross-exchange arb trading had already been done. It's exceptionally difficult to squeeze any profit out of this kind of very crowded trade. There have even been Twitter bots that have come and gone which automatically identify opportunities and broadcast to the whole world how an aspiring entrepreneur can lose a lot of money trying to make fractions of a penny if they act now.