Be careful using ACV.
I attended one of Bill's webinars and bought from his company a couple indicators. He was gracious enough to allow me to also join him in a training room for a couple days. He seems to be a very good guy and a knowledgable trader.
Using ACV, however, can be trickier than it seems at first. Bill's advice on the subject at it's core is a theory of:
When the ratio of ask volume size for accumulated quotes (level 0-4) vs bid volume size is greater than 2:1, go long. Prices should rise.
Vice versa to go short.
In actual practice, I have coded this in NeoTicker with level 2 order book data and charted it with some of the E-mini's.
The results are as follows: *often*, when the ACV hits 2:1 for the first time after being inconclusive (ratio < 2:1) or chopping around (or even weighted in the other direction), it will result in a quick, sharp move of 3-10 ticks. Since Bill himself admits that he uses this method to "scalp for afew ticks" (he actually says that he only goes for TWO ticks usually), I can honestly say that in testing and live usage, he is generally RIGHT. HOWEVER, if you are scalping for 2 ticks, you could likely catch them using one of a hundred other methods that are at least as dependable, possibly even moreso.
The DANGER with ACV is that in my testing and usage, once the ratio hits 3:1 or more (and it does, believe it or not) or after it has stayed >2:1 for an extended period (which probably was a nice trending move), the price is equally likely to experience a LARGE and FAST reversal. So you must be nimble and not get greedy, or you will get caught in a reversal and give up far more ticks than the scalping gained you.
The PROBLEM is that without charting the ACV (just going by the streamed Ninja data) there is no way for you to know how long the ratio has been at 2:1. Unless you are staring at it every second of the day

Therefore if you look at it and see a 2:1 ratio, you can't tell if that ratio has held true for how long.....and believe me, the longer it stays there, the more likely of a reversal. In my own trading, I have found it more productive to look for 3:1 or greater ratio's, and look for an imminent reversal to 1:1 or greater in the OTHER direction. Just my .02.
W