For all i know is that the only info on this topic is in the attached: http://www.elitetrader.com/vb/attachment.php?s=&postid=1369939
http://www.elitetrader.com/vb/showthread.php?s=&threadid=38777&perpage=40&pagenumber=1 Start here, go through as much or as little material as you want. The screenshot posted is showing the % of the volume based on time of day and also different volume conditions dry up, first rising, and peak which are used as signals for getting in / out at natural parts of a trend cycle. It is also useful for is extrapolating when we are likely to get a breakout and hoping on board BEFORE that breakout. You may disagree/agree with the above statement. To understand it, you need context, which is what the thread provides.