Here's a theory, only somewhat in jest --
what if there was a short covering panic this morning, to the tune of about 350k shares. Then when it went above the noretreat target number of 1.08, all the shares that had been covered were re-shorted, especially up around 1.15 or so.
Then, because everyone thinks it's possible we might get news tomorrow or Friday, and any short would be crazy to hold short overnight, they covered the new shorts at 1.05 or less (playing for nickels and dimes).
That would account for a bit over a million of today's volume.