20% Down for a QRM Mortgage? Here Come the Conduits?

Regulators have supposedly inked a risk retention rule which says this:  borrowers will have to make at least a 20% downpayment to meet criteria that exempts lenders from retaining a portion of the loan when selling it into the secondary market. The story comes from our sister publication, American Banker. At this time there are few details, which means the role of mortgage insurers in risk retention is unclear. Could it be that if a mortgage insurance policy is written on a 90% LTV loan that it too will be exempt from risk retention and therefore be considered a 'qualified residential mortgage'? We don't know, but the details should be forthcoming and hopefully soon. Meanwhile, all those jumbo conduits we've been hearing about (none of which have done deals except for Redwood Trust) are waiting for September 1 when the Fannie Mae/Freddie Mac loan limit drops from $729,750 to $625,500…