I don't know if you are using the ihub print that tells you if something is a buy or a sell. I am not a fan of it. Remember, that is an assumption. I can tell you that I buy on the bid a lot. I might not get an immediate fill or I may miss a fill completely but often I do fill. So if you saw a print of my buy on the bid would you consider that sell volume?
News 
Market Data 
Discover 
