Question Summary:
I would like to know if it is permissable to buy other foreign currencies as an investment?

Question Detail:

I would like to know if it is permissable to buy other foreign currencies as an investment? 
For example: In South Africa the rand is fluctuating a lot so I would like to buy dollars/pounds/euros as a security against the devaluing of the rand
I would like to do this by opening a savings account in a different country in their currency (a more econommically stable) country? 

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh
It is permissible to purchase other currencies in different geographical locations. We advise you to search for Shariah Compliant dollar/pound/euro denominated savings accounts overseas. Various offshore locations provide for Shariah Compliant savings accounts such as United Kingdom and United Arab Emirates.
 
And Allah Ta’āla Knows Best
 
Ismail Desai,
Darul Iftaa
 
Checked and Approved,
Mufti Ebrahim Desai.