Look at the action (lack of) in this past hour or

Look at the action (lack of) in this past hour or so. I seriously just checked to see if it had been halted. Tremendous volume and now in the last hour nothing? ? ? ? We've seen this before in the afternoons, not that I know what it means.

At 3:04 eastern time, 611,970 shares traded. Let's see when there is another trade.