The same currency pair on two exchanges with different prices fundamentally presents an opportunity for profitable arbitrage trades:
1. A simple example using Bitcoin: on November 13, 2018, at 10:31 a.m. Paris time, the Bitcoin was quoted €5600.9700 on the Bitstamp exchange and €5785.9000 on the Exmo exchange.
--> By buying and selling simultaneously on these two exchanges, the gross gain (excluding trading costs) was 3.3%.
2. A second example, which was taken a few minutes later on Etherum (second crypto in terms of valuation) $204.94000 on Kraken and $212.13000 on Exmo.
--> That is a 3.51% immediate gross gain.
3. One last example, a few minutes later, on Dash: $160.0800 on Cex and $163.8400 on Bitfinex.
--> That is a 2.35% immediate gross gain.
Even after deducting significant costs, the net profit remains attractive.