This is my favorite bizarre chart that lets me know not only how much volume there was on a given day but when it happened and how the day compared to other days. It is simply an hourly histogram of NYSE volume.
Each bar is 60 minutes of trading except the bottom-most bars, which represent 9:30 to 10:00 NYT. The top-most bars represent 4:00 - 4:15 - don't ask me why they do it this way (ask eSignal).
What I see here for June 19 is an average total for the day compared to the past five days with the distorted set of bars for last Friday's quadruple witching options explorations going off the top of the chart.
Next, I see that the final hour 3:00 - 4:00 is always the biggest of the day, again witching days excluded.
Finally, I see that the biggest change from the same hour the previous day occurred at 2:00 - 3:00 (highlighted in gold). What was happening then? Stock prices fell abruptly from their high water mark of the day. Interesting. There was a mini-stampede to get out near the end of the day.
What happened volume-wise as the market was scooting up in the first half hour of the day? Nothing. Volume was barely more than Monday's volume
You can interpret it any way you like and normally I'd say the market was getting skittish.
But it does not matter. The Fed holds your jewels in its sweaty little hands. Will they squeeze or massage lovingly?