Mintpal data is unavailable but I bet that wasn't less than half the polo volume. So approx 1500btc worth of coins traded. Quite a lot actually.
XMR was not traded on Mintpal at the time of the rally to 0.01, IIRC the rally was hyped because of Mintpal anticipation.
Hmmmm.
Just looked. Yes you're right my mistake, it was Trex that was also trading XMR at the time and that did have several 100btc of volume around that high.