All I can think of, with less than 1 month to go eliminating...

All I can think of, with less than 1 month to go eliminating factors like large exchange rate movements, is that maybe the new shares will plummet in value on the german exchange once they are tradeable. And there will also be some hassle involved to create some sort of international brokerage account to transfer them into that before you can sell them. But you can use commsec international or IBKR for that, so it's not that big a deal.

I've asked several business-minded friends who don't see anything glaringly obvious that is discounting the price of these by 50%.