Here are a few possible reasons:
The contract in question has expired
There are multiple contracts available for trading on the exchange, and we allow you to trade only one of them. Each contract has its own term, and when this term expires, we substitute the previous contract with the next one.
The prices of these two contracts are generally different, hence the short-term difference in prices compared to other data sources. Still, if you compare our quotes to those on an exchange, you'll see that they coincide. As a result, the quotes we provide are real market quotes.
To see the expiry date and other current contract specs, please refer to the Instrument Specifications (Advanced - Expiry date).
The quotes are given for different contracts
Some assets or instruments are traded on multiple exchanges. For example, the Nikkei 225 is traded on both the Chicago Mercantile Exchange and the Tokyo Stock Exchange, with possible differences in quotes and conditions between the two.
Even in a single exchange, there may be several contracts with the same underlying asset traded at the same time but with different expiry times.
To view details about each particular contract with a link to the respective exchange, please refer to the Contract Specifications (Advanced - Venue).