That's partly the Aussies Fault. Cross listing stocks on multiple foreign exchanges in reality is rather complicated. These are not separate shares owned by each stock exchange for the benefit of their Investors only. In theory in a perfect market the price ending from one exchange is supposed to be adjusted and started At the new price in the next exchange. The complications get even worse when one exchange hasn't even finished before another 1 starts. , In theory there eventually supposed to equalize between the multiple exchanges. In reality this equalized price can take hours days and sometimes even weeks to manifest the true value. When the Aussies panic dumped the stock after the update, It served to give US market makers an excuse to bring the price in at the adjusted value.
There's no rule that says it had to be at the same Deep discount but I'm sure they took advantage of the situation laid in their laps. Of course a good share of the fault also goes to whoever wrote that update!!!
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