The primary explanation for discrepancies in bitcoin price across different exchanges is the fact that, as a decentralized digital currency, there is no standard or global bitcoin price at any given period of time.
It isn’t pegged to the USD or to any other fiat currency, nor is it linked to a particular country or to an exchange. As with commodities of all types, supply and demand vary depending upon the time and the market, and the price of bitcoin fluctuates as a result.
Given that there is no global standard for the price of a single bitcoin, how can investors be sure that Google, a digital currency exchange, or another price tracker is accurate? The short answer is that these prices are not, in fact, guaranteed to be accurate at all. A reason for this is that most bitcoin price trackers calculate an average estimate or a recently-traded price of bitcoin based on the transaction history of a prominent bitcoin exchange. Google, for example, bases its figures off of the Coinbase API, which is why it links the value of bitcoin to a U.S. dollar.
Beyond the (hopefully modest) inaccuracies built into a price tracker or search engine when it comes to estimating the cost of a single bitcoin, investors should also keep in mind that the actual price of buying that coin in an exchange is likely to be higher.
The reason for this is that most exchanges require some type of transaction fee. This is typically very modest in comparison to the price of a bitcoin, particularly as bitcoin’s value has skyrocketed in recent months, but it does further introduce inaccuracies into the price that you may see listed.