I agree that order flow is useful (or at least the price and volume part of it), but not sure why it is necessary to track bid / ask traded volume or open orders. In that situation that you describe of 1480 orders hitting the bid and no follow through...what would price and volume be doing? You'd see lots of volume and price stopped at a level. What additional information does the bid / ask tell you? I've looked at 4 levels of the order book when watching futures (CL or ES). What I see is volume continually refreshed at both levels until it is instantly no longer refreshed and price moves. So I can see how volume and price can be predictive of price. But I have not found any advantage to looking at the order book or tracking whether trades execute on the bid or ask. For an HFT firm, there likely is an advantage, but the order book moves so fast, I suspect network latency would be a disqualifier for any algorithm that a retail trader could develop. Of course, if a retail trader has managed to find consistent profitability by applying such a strategy and is laughing at this post, that's awesome.