How are fee conversion rates calculated?

Q:

How do we determine the conversion rate in converting the volume of an order in quote currency to the volume in USD. e.g. How do we go from volume in EUR to volume in USD?

A:

The conversion to USD for the purpose of calculating your 30 day trade volume in USD is done using spot prices on our exchange. Spot is taken as the mid-point of bid + ask.

To get the spot rate for something like EUR/USD, which we don't have a market for, we use the spot for XBT/EUR and XBT/USD to get it. In a few cases we might not be able to get the implied spot rate that way and for those cases we pull the rate from a third party site.