Well the spread was .0004 x .0006 for most of the day so it just took a sell at .0004 to move us down.
There was a trade at .0004 at about 3:40 for 2.35 mil that was mirrored up to .0005 9 seconds later, then another trade at .0004 (5.35. mil) 6 seconds after that. That was the last trade. So there was a trade at the ask in there.