I have seen many times that in local market BTC price are quite change from international market. Once the price of BTC in Indian market (Zebpay)used to be 2-3 lacks more than the price in bitfinnix. But todayBTC price in Indian price is 1 lack less than the price in bitfinnix , which is big ammount in terms of percentage.
The causes of big difference in bitcoin price in local markets is demand and supply, sometimes at the local country the amount of bitcoin is small and the people who want buy bitcoin is big it will makes the price of bitcoin increase and at same place around the world the people who want buy bitcoin is small, it will makes price of bitcoin goes down.
I think that these trading sites also get benefited from such type of news . First trading increases drastically so they get good transaction charges and secondly the take advantages from such activities and purchase crypto at low rate.Later on local price tried to settle as international price.