Forrest, spot on.You will see much the same thing when an...

Forrest, spot on.

You will see much the same thing when an australian broker buys on behalf of an overseas client, particularly with a low volume stock such as CST.
The broker just pecks away during the day endeavouring to buy enough to fill the client's (early morning AEST) order, then at the end of the day they pass the total bought across to the client at the VWAP as a separate transaction.
Thus there is always a function of double counting as far as volume goes when you see overseas orders.

Just speculation but it could have just been a US investor caught by the proverbials in the deleveraging maelstrom that is going on worldwide but particularly in the US.

regards, EB