Firstly they are RMBS and XCP, second the aust mortgages underpinning them continue to have default rates far lower than their US equivalents. Moodys have reaffirmed RHG Prime 1 rating on its debt after the crunch & the market in the us is starting to return for top quality debt - rams debt is of this sort and doesn't contain the same risky loans based on unrealistic LVR and 'liar loans'.