Bitcoin Forum

How the trading platforms like Poloniex, Kraken etc... knows the buy and sells on the market.
Are they connected together through some sort of API?
How can they all have the same market price at the same time?

Anyone could direct me to a place where the communication between the different exchanges is explained?

Thanks

They actually don't. Price difference can be quite high actually. I remember a few weeks back when ETH was crashing, it reached 255$ on Bithumb (Korean exchange I believe) while on western exchanges it didn't really go below 270.

I don't really know the technical details, but price are not the same across all exchanges.

Thanks for your reply. I work with smart contract in the Ethereum blockchain. Smart contracts have to use the ERC20 standard that is a simple class for monetary transfer.
I would like to understand how the exchanges are using the smart contrats. I guess that they are reading the addresses using the ERC20 standard, but there is not many info about how they interact, calculate the current prices of the tokens etc.

If you are asking why they are same price because there are some traders are buying low in other trading site and then going to other trading site just to sell there so if the price was sold there until the price of the other trading site will be the same as price as other.. i think you don't need to know the chat just monitor the market price of every trading site so that if you can buy cheap in 1 site and you can sell it for better price in other site just do it you can gain profit with that way..

Every exchanger has its own Api. They provide that to services like coinmarketcap and others. So cryptopia for example compares the prices to other exchangers.
On coinmarketcap you can see all listed markets at each trading pair.

They are not connected to each other. It is differences in the market price and especially in their volumes and you can see it in the coin market cap. The different interest by the traders will not make the price will be same, I think that there is a little gap between the price of every exchange site.

Every trading site has its own buying and selling order book. This decides the price on each seperate exchange. They are in fact not connected to eachother.

Yeah you got the point and i think they are just relaying in almost all exchange site and give an average price for bitcoin..
And like other said there are different value or price of every exchange site there is a little gap but if you are early and buy cheap in other site you can sell it in other exchange  site like other said you can gain a good profit if you are active trader.

I think that is a problem. I had one website with ETH at $315 and another at $324.
It seems that some exchanges are voluntary showing a price lower so that they can pocket the difference!

It's not a problem. Arbitrage traders generally correct these imbalances pretty quickly. They run bots on several exchanges, reconciling accounts on each one to take advantage of the price gaps between exchanges, rather than the volatility itself. Exchanges could do arbitrage, too, and I don't see any major problem with it.

I definitely think some exchanges push their prices higher or lower to run people's stops or margin call their traders, though. That's a problem, but it'll continue to happen on unregulated exchanges. I'm not sure I even trust the regulated ones. :P

There is no communication nor relation between exchanges ofcourse when the coins were being pump or dump in one exchange with the same as otger exchange it will follow. Why? because its the nature of coins thats why sometimes we can see a delayed pump or dump in other exchanges they are following the price and the other traders were doing an arbitrage (transferring same coins) into other exchange to sell in good price.

If you search very well you will understand that price are not the same across all the exchangers platforms. Arbitrage traders  take advantage of this to make great profit from the difference from those exchangers price. There never has the same price.

I personally have been trading some ERC20 tokens on various exchanges very recently and all of them have a variable price which depend upon the pricing of the token during the ICO and how the coin is developing on its flowchart. There usually no link between exchanges but prices would be almost similar in most cases as everyone would buy for the lowest and sell for the highest possible price.

Thanks all for your answers...