Bitcoin Forum

I'm tracking BTC rates and they are all different??

That's because they are all separate entities concentrated to the same thing - the bitcoin market price.
You notice when you check the price on preev you get the average price among the bitfinex and bitstamp price? You can click on those two at the top and see them clearly shown and the bitfirex one is always the larger of the two.
Every exchange has their own price but it should not deviate from being 5-8% difference of each other or there are problems.
You check the price on yobit lately. Now that is way off but most on here will tell you that is not a real exchange compared to the bigger ones that you have mentioned. So it does not count. So go figure. :-\

Different platforms of exchange mean different transactions so different prices!
But what's interesting is that it's a very specific job of trading to balance the prices. It's called arbitrage trading, the goal is to use those little differences (I'm saying little even if they can be of 30$ because you have to consider the fees in each exchanges) to exchange btc and/or dollars from platforms to platforms. You buy where price is low and sell on a platform with higher prices. It's difficult, needs you to have a very good knowledge of the fees ^^

Thank you Arcteryx and Valta4065 - Very helpful both of you! ;D

Coindesk is a news site and reports an average price among different exchanges, i don't remember the details but you can read it on their site i think it was called BPI

cointelegraph is also news site and i have never bothered checking it because it is pretty bad, but it also takes the price from somewhere similar to coindesk and reports it.

poloniex doesn't even have a USD market, it instead has USDT which is an altcoin with the same price of USD and since it is a different market in many aspects the price is usually different too.

Kraken is a bitcoin/fiat exchange and that price is live and reliable among these. but if i am not mistaken it doesn't have USD but only has EUR markets (have to double check)

and as for exchange prices (bitfinex, bitstamp,...) differences as other mentioned since they are different and not connected to each other the prices become different from time to time but since they are all trading same thing bitcoin versus fiat the price balances out fast enough.

In addition to what other has said, Bitcoin price on those sites vary because of the force of supply and demand from the region those sites are residents. Arbitrary traders take advantage of this price difference and earned their living by buy bitcoin low from a particular site and exchange it high in another site.

supply and demand is different on different exchange, but all the small exchange follow the biggest one, use preev for the average value...

but you can take advantage of this and do arbitrage if the difference is very noticeable, like with btc-e and other, better to do it with a bot, because manually you lose precious time

Thank you all!