Margin call capitulation?, page-28

Usually if you had a currency risk you would buy some sort of currency insurance similar to exporters, to at least limit your downside.

For an upfront premium these foreign Currency Options offer a range of methods for limiting the risks associated with foreign exchange exposure. Option holders can obtain 'Insurance' against adverse movements in exchange rates while maintaining the ability to profit should the exchange rate move favourably. A Foreign Currency Option grants a customer the right, but not the obligation, to buy or sell foreign currency at a specified price within a specified period of time.  

I can remember selling this stuff to clients many years ago.

At the moment if non-hedged entities are leaving Aussie shares due to weakened currency, the contrary can be true, Aussie shares become cheaper in foreign currencies.  Also AUD is offering interest rates a few percent above most other countries.

The reason that overseas share holders might leave is if they think the AUD is at risk of further declines, of they are not hedged/insured.