where does FX volume data come from?

[BobbyChow]

Noob question:

I read somewhere that because FX has no central exchange there's no volume data for each tick.

But I just downloaded some data with Tickstory, and it has bid/ask volume. Is this data correct? Where does it come from anyway?

[tickstory]

Hi Bobby,

The Bid/ask volume data represents the volume on the bid/ask side of the order book at any given moment. You can find more details on this thread.

Thanks