Some buyout rumor, I guess. You would have had to be sitting in front of your screens and paying attention to a screaming scanner. I was having my teeth cleaned at exactly this time today. Risk / reward wasn't so wonderful as it turned out.
As I note on the chart, the old candlevolume is a poor (man's) substitute for the slick new "Footprint" charts. My buddy @tradergav informs me that they are known as Numbers Bars in Sierra Chart.