Trade, the only days recently that I know of that had anything close to that kind of voume was the day (3/6) that Amy sold us down the river and the trading day after that.
I believe on 3/6 and 3/7, we may have had around a total of six million shares traded with the most of that on 3/6. I have never seen anything that heavy since or remotely close to that number, other than the days I just mentioned.