One thing to consider in doing arbitrage is the block confirmation time. Nowadays, it average about ~40
https://blockchain.info/charts/avg-confirmation-time?timespan=1days minutes to find each block. Given that time span, bitcoin's price has already flactuated like crazy. Another thing good to note, is the minimum confirmation before a certain btc be allowed to withdraw unto the secondary btc exchanger.
The chances for going into massively profitable arbitrage trading is being killed by these types of practical problems. Many traders here has reported about getting struck with some exchanges regulations against KYC and now a days bitcoin confirmation delay must be a very big hurdle to go for profitable arbitrage trading.
I tried few times within my local exchanges even it involves bank transfers, due to some prior experiences I was able to crack some profits. I targeted big gaps, but when I got ready prices got little near in both the exchanges.