Possibly the volume is not as high as shown when you take into account the MM's arbitraging between U.S. @ Cdn markets to pick up their .005 cents per share.

This means the same shares may be showing up twice in the arbitrage.

Not absolutely certain on just how this arbitration is set up but it appears that they are bought and sold on one exchange and then as they say arbitraged thru another exchange via computer programing for small brokerage profits.

With these shares possibly showing up on trading volumes for both index's it could reduce the overall daily volume

Therefore extending the time required for any share transfer.

JMHO

Sm