I think your theory is very valid. I went back and looked at outstanding warrants from the last Q (7-31) compared to outstanding at the proxy (10-31).
7-31
Series A 7,680,000
Series C 12,000,000
Series D 10,622,460
10-31
Series A 7,680,000 (0)
Series C 11,540,900 (-459,100)
Series D 2,584,174 (-8,038,286)
It is apparent that the Series D ($1.60) warrants are being exercised and the Series C (&1.28) are being held.
I would speculate that the balance of the D’s hit the float this week.
interesting that the Series C expire 1 year from issuance.