Does DOM trading using broker data make any sense?

External question — Quantitative Finance Stack Exchange Author: 4pie0 Original post: https://quant.stackexchange.com/questions/7421 License: CC BY-SA 3.0 — https://creativecommons.org/licenses/by-sa/3.0/ Adaptation: HTML converted to plain text; contact email addresses removed. Can I use DOM information from Interactive Brokers? Does it make sense? I assume that it makes sense to apply some volume based algorithms only then when you know this order book, that you can get info about is really market book. If it represents the main part of the market, otherwise this information is negligible in front of all big names doing trading and in light of their orders which you are not aware of. What information gives me volume info from IB? Can I make assumption about FX order flow based on their data feed? We can see here that IB covers all important exchanges, but what is their volume? The sum of the all noticed volumes on exchanges? Please could you clarify this issue a little as it was always confusing to me.

External answer — Quantitative Finance Stack Exchange Author: bluelou Original post: https://quant.stackexchange.com/a/7464 License: CC BY-SA 3.0 — https://creativecommons.org/licenses/by-sa/3.0/ Adaptation: HTML converted to plain text; contact email addresses removed. Assuming your question is about using the FX 'volume' you see in a broker's DOM or T&S window, you probably can't infer much about order flow in the way you can with other instrument types. FX volume and tick data are not equivalent to what you will see for other instruments. That is, unless the feed is coming from a FX ECN like HotSpot or Currenex, the volume and ticks you're seeing are just quotes, not completed trades.