well, there is an exchanger cartel. The biggest ones agreed to collaborate each other and here we are. It is the same BTC price despite the fact that BTC is NOT a centralized market. IT IS NOT possible a such thing while there is not any central authority. 
example : Coinbase and Bistamp are very tightly coupled. They have the same shareholders
Look to ALL the biggest exchangers and you will see a similar price even it's from Singapore, China, USA or Europe... HOW IS it possible if there is no cartel?
example : Coinbase and Bistamp are very tightly coupled. They have the same shareholders
Look to ALL the biggest exchangers and you will see a similar price even it's from Singapore, China, USA or Europe... HOW IS it possible if there is no cartel?
All forex is decentralised. Try buying GBP in Singapore, China, the USA or Europe and you'll see a similar price.
The reason prices are similar is due to arbitrage: if 1 GBP costs less in Singapore than it does in China, arbitrageurs will buy GBP in Singapore and sell it in China. The same thing happens with BTC.
I'm not saying that there isn't a cartel operating, I really don't don't know. But this isn't evidence of it.